diff --git a/electron/api/routes/channels.ts b/electron/api/routes/channels.ts
index 96ce52aaa..3197d20bc 100644
--- a/electron/api/routes/channels.ts
+++ b/electron/api/routes/channels.ts
@@ -101,9 +101,11 @@ async function isLegacyConfiguredAccountId(channelType: string, accountId: strin
 async function validateCanonicalAccountId(
   channelType: string,
   accountId: string | undefined,
-  options?: { allowLegacyConfiguredId?: boolean },
+  options?: { allowLegacyConfiguredId?: boolean; required?: boolean },
 ): Promise<string | null> {
-  if (!accountId) return null;
+  if (!accountId) {
+    return options?.required ? 'accountId is required' : null;
+  }
   const trimmed = accountId.trim();
   if (!trimmed) return 'accountId cannot be empty';
   if (isCanonicalOpenClawAccountId(trimmed)) {
@@ -122,8 +124,12 @@ async function validateAccountIdOrReply(
   res: ServerResponse,
   channelType: string,
   accountId: string | undefined,
+  options?: { required?: boolean },
 ): Promise<boolean> {
-  const error = await validateCanonicalAccountId(channelType, accountId, { allowLegacyConfiguredId: true });
+  const error = await validateCanonicalAccountId(channelType, accountId, {
+    allowLegacyConfiguredId: true,
+    required: options?.required,
+  });
   if (!error) {
     return true;
   }
@@ -313,8 +319,58 @@ async function ensureScopedChannelBinding(channelType: string, accountId?: strin
 
   // Legacy compatibility: if accountId matches an existing agentId, keep auto-binding.
   if (agents.agents.some((entry) => entry.id === accountId)) {
+    await migrateLegacyChannelWideBinding(storedChannelType);
     await assignChannelAccountToAgent(accountId, storedChannelType, accountId);
+    return;
   }
+
+  await migrateLegacyChannelWideBinding(storedChannelType);
+}
+
+async function migrateLegacyChannelWideBinding(channelType: string): Promise<void> {
+  const explicitDefaultOwner = await readChannelBindingOwner(channelType, 'default');
+  const legacyOwner = await readChannelBindingOwner(channelType);
+  if (!legacyOwner) {
+    return;
+  }
+
+  const agents = await listAgentsSnapshot();
+  const validAgentIds = new Set(agents.agents.map((agent) => agent.id));
+  const defaultOwner = explicitDefaultOwner && validAgentIds.has(explicitDefaultOwner)
+    ? explicitDefaultOwner
+    : (legacyOwner && validAgentIds.has(legacyOwner) ? legacyOwner : null);
+
+  if (defaultOwner) {
+    await assignChannelAccountToAgent(defaultOwner, channelType, 'default');
+  }
+
+  // Remove the legacy channel-wide fallback so newly added non-default
+  // accounts do not silently inherit default-agent routing.
+  await clearChannelBinding(channelType);
+}
+
+async function readChannelBindingOwner(channelType: string, accountId?: string): Promise<string | null> {
+  const config = await readOpenClawConfig();
+  const bindings = Array.isArray((config as { bindings?: unknown }).bindings)
+    ? (config as { bindings: unknown[] }).bindings
+    : [];
+
+  for (const binding of bindings) {
+    if (!binding || typeof binding !== 'object') continue;
+    const candidate = binding as {
+      agentId?: unknown;
+      match?: { channel?: unknown; accountId?: unknown } | unknown;
+    };
+    if (typeof candidate.agentId !== 'string' || !candidate.agentId.trim()) continue;
+    if (!candidate.match || typeof candidate.match !== 'object' || Array.isArray(candidate.match)) continue;
+    const match = candidate.match as { channel?: unknown; accountId?: unknown };
+    if (match.channel !== channelType) continue;
+    const bindingAccountId = typeof match.accountId === 'string' ? match.accountId.trim() : '';
+    if ((accountId?.trim() || '') !== bindingAccountId) continue;
+    return candidate.agentId;
+  }
+
+  return null;
 }
 
 interface GatewayChannelStatusPayload {
@@ -1145,11 +1201,19 @@ export async function handleChannelRoutes(
   if (url.pathname === '/api/channels/binding' && req.method === 'PUT') {
     try {
       const body = await parseJsonBody<{ channelType: string; accountId: string; agentId: string }>(req);
-      const validAccountId = await validateAccountIdOrReply(res, body.channelType, body.accountId);
+      const validAccountId = await validateAccountIdOrReply(res, body.channelType, body.accountId, { required: true });
       if (!validAccountId) {
         return true;
       }
-      await assignChannelAccountToAgent(body.agentId, resolveStoredChannelType(body.channelType), body.accountId);
+      const agents = await listAgentsSnapshot();
+      if (!agents.agents.some((entry) => entry.id === body.agentId)) {
+        throw new Error(`Agent "${body.agentId}" not found`);
+      }
+      const storedChannelType = resolveStoredChannelType(body.channelType);
+      if (body.accountId !== 'default') {
+        await migrateLegacyChannelWideBinding(storedChannelType);
+      }
+      await assignChannelAccountToAgent(body.agentId, storedChannelType, body.accountId);
       scheduleGatewayChannelSaveRefresh(ctx, body.channelType, `channel:setBinding:${body.channelType}`);
       sendJson(res, 200, { success: true });
     } catch (error) {
diff --git a/electron/utils/agent-config.ts b/electron/utils/agent-config.ts
index fb5d5a244..9dd0309ac 100644
--- a/electron/utils/agent-config.ts
+++ b/electron/utils/agent-config.ts
@@ -280,29 +280,33 @@ function upsertBindingsForChannel(
   agentId: string | null,
   accountId?: string,
 ): BindingConfig[] | undefined {
-  const normalizedAgentId = agentId ? normalizeAgentIdForBinding(agentId) : '';
+  const normalizedAccountId = accountId?.trim() || '';
   const nextBindings = Array.isArray(bindings)
     ? [...bindings as BindingConfig[]].filter((binding) => {
       if (!isChannelBinding(binding)) return true;
       if (binding.match?.channel !== channelType) return true;
-      // Keep a single account binding per (agent, channelType). Rebinding to
-      // another account should replace the previous one.
-      if (normalizedAgentId && normalizeAgentIdForBinding(binding.agentId || '') === normalizedAgentId) {
-        return false;
-      }
-      // Only remove binding that matches the exact accountId scope
-      if (accountId) {
-        return binding.match?.accountId !== accountId;
+
+      const bindingAccountId = typeof binding.match?.accountId === 'string'
+        ? binding.match.accountId.trim()
+        : '';
+
+      // Account-scoped updates must only replace the exact account owner.
+      // Otherwise rebinding one Feishu/Lark account can silently drop a
+      // sibling account binding on the same agent, which looks like routing
+      // or model config "drift" in multi-account setups.
+      if (normalizedAccountId) {
+        return bindingAccountId !== normalizedAccountId;
       }
+
       // No accountId: remove channel-wide binding (legacy)
-      return Boolean(binding.match?.accountId);
+      return Boolean(bindingAccountId);
     })
     : [];
 
   if (agentId) {
     const match: BindingMatch = { channel: channelType };
-    if (accountId) {
-      match.accountId = accountId;
+    if (normalizedAccountId) {
+      match.accountId = normalizedAccountId;
     }
     nextBindings.push({ agentId, match });
   }
diff --git a/tests/e2e/channels-binding-regression.spec.ts b/tests/e2e/channels-binding-regression.spec.ts
new file mode 100644
index 000000000..f009cb5bc
--- /dev/null
+++ b/tests/e2e/channels-binding-regression.spec.ts
@@ -0,0 +1,130 @@
+import { completeSetup, expect, test } from './fixtures/electron';
+
+test.describe('Channels binding regression', () => {
+  test('keeps newly added non-default Feishu accounts unassigned until the user binds an agent', async ({ electronApp, page }) => {
+    await electronApp.evaluate(({ ipcMain }) => {
+      const state = {
+        nextAccountId: 'feishu-a1b2c3d4',
+        saveCount: 0,
+        bindingCount: 0,
+        channels: [
+          {
+            channelType: 'feishu',
+            defaultAccountId: 'default',
+            status: 'connected',
+            accounts: [
+              {
+                accountId: 'default',
+                name: 'Primary Account',
+                configured: true,
+                status: 'connected',
+                isDefault: true,
+                agentId: 'main',
+              },
+            ],
+          },
+        ],
+        agents: [
+          { id: 'main', name: 'Main Agent' },
+          { id: 'code', name: 'Code Agent' },
+        ],
+      };
+
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      (globalThis as any).__clawxE2eBindingRegression = state;
+
+      ipcMain.removeHandler('hostapi:fetch');
+      ipcMain.handle('hostapi:fetch', async (_event, request: { path?: string; method?: string; body?: string }) => {
+        const method = request?.method ?? 'GET';
+        const path = request?.path ?? '';
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        const current = (globalThis as any).__clawxE2eBindingRegression as typeof state;
+
+        if (path === '/api/channels/accounts' && method === 'GET') {
+          return { ok: true, data: { status: 200, ok: true, json: { success: true, channels: current.channels } } };
+        }
+        if (path === '/api/agents' && method === 'GET') {
+          return { ok: true, data: { status: 200, ok: true, json: { success: true, agents: current.agents } } };
+        }
+        if (path === '/api/channels/credentials/validate' && method === 'POST') {
+          return { ok: true, data: { status: 200, ok: true, json: { success: true, valid: true, warnings: [] } } };
+        }
+        if (path === '/api/channels/config' && method === 'POST') {
+          current.saveCount += 1;
+          const body = JSON.parse(request?.body ?? '{}') as { accountId?: string };
+          const accountId = body.accountId || current.nextAccountId;
+          const feishu = current.channels[0];
+          if (!feishu.accounts.some((account) => account.accountId === accountId)) {
+            feishu.accounts.push({
+              accountId,
+              name: accountId,
+              configured: true,
+              status: 'connected',
+              isDefault: false,
+            });
+          }
+          return { ok: true, data: { status: 200, ok: true, json: { success: true } } };
+        }
+        if (path === '/api/channels/binding' && method === 'PUT') {
+          current.bindingCount += 1;
+          const body = JSON.parse(request?.body ?? '{}') as { channelType?: string; accountId?: string; agentId?: string };
+          if (body.channelType === 'feishu' && body.accountId) {
+            const feishu = current.channels[0];
+            const account = feishu.accounts.find((entry) => entry.accountId === body.accountId);
+            if (account) {
+              account.agentId = body.agentId;
+            }
+          }
+          return { ok: true, data: { status: 200, ok: true, json: { success: true } } };
+        }
+        if (path === '/api/channels/binding' && method === 'DELETE') {
+          current.bindingCount += 1;
+          return { ok: true, data: { status: 200, ok: true, json: { success: true } } };
+        }
+        if (path.startsWith('/api/channels/config/') && method === 'GET') {
+          return { ok: true, data: { status: 200, ok: true, json: { success: true, values: {} } } };
+        }
+
+        return {
+          ok: false,
+          error: { message: `Unexpected hostapi:fetch request: ${method} ${path}` },
+        };
+      });
+    });
+
+    await completeSetup(page);
+
+    await page.getByTestId('sidebar-nav-channels').click();
+    await expect(page.getByTestId('channels-page')).toBeVisible();
+    await expect(page.getByText('Feishu / Lark')).toBeVisible();
+
+    await page.getByRole('button', { name: /Add Account|添加账号|アカウントを追加/ }).click();
+    await expect(page.getByText(/Configure Feishu \/ Lark|dialog\.configureTitle/)).toBeVisible();
+
+    const accountIdInput = page.locator('#account-id');
+    const newAccountId = await accountIdInput.inputValue();
+    await expect(accountIdInput).toHaveValue(/feishu-/);
+    await page.locator('#appId').fill('cli_test');
+    await page.locator('#appSecret').fill('secret_test');
+
+    await page.getByRole('button', { name: /Save & Connect|dialog\.saveAndConnect/ }).click();
+    await expect(page.getByText(/Configure Feishu \/ Lark|dialog\.configureTitle/)).toBeHidden();
+
+    const newAccountRow = page.locator('div.rounded-xl').filter({ hasText: newAccountId }).first();
+    await expect(newAccountRow).toBeVisible();
+    const bindingSelect = newAccountRow.locator('select');
+    await expect(bindingSelect).toHaveValue('');
+
+    await bindingSelect.selectOption('code');
+    await expect(bindingSelect).toHaveValue('code');
+
+    const counters = await electronApp.evaluate(() => {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const state = (globalThis as any).__clawxE2eBindingRegression as { saveCount: number; bindingCount: number };
+      return { saveCount: state.saveCount, bindingCount: state.bindingCount };
+    });
+
+    expect(counters.saveCount).toBe(1);
+    expect(counters.bindingCount).toBe(1);
+  });
+});
diff --git a/tests/unit/agent-config.test.ts b/tests/unit/agent-config.test.ts
index d939afb03..75e739055 100644
--- a/tests/unit/agent-config.test.ts
+++ b/tests/unit/agent-config.test.ts
@@ -379,7 +379,7 @@ describe('agent config lifecycle', () => {
     expect(snapshot.channelAccountOwners['telegram:default']).toBe('main');
   });
 
-  it('replaces previous account binding for the same agent and channel', async () => {
+  it('keeps sibling account bindings for the same agent and channel', async () => {
     await writeOpenClawJson({
       agents: {
         list: [
@@ -404,10 +404,40 @@ describe('agent config lifecycle', () => {
     await assignChannelAccountToAgent('main', 'feishu', 'alt');
 
     const snapshot = await listAgentsSnapshot();
-    expect(snapshot.channelAccountOwners['feishu:default']).toBeUndefined();
+    expect(snapshot.channelAccountOwners['feishu:default']).toBe('main');
     expect(snapshot.channelAccountOwners['feishu:alt']).toBe('main');
   });
 
+  it('preserves original agentId casing when persisting bindings', async () => {
+    await writeOpenClawJson({
+      agents: {
+        list: [
+          { id: 'MainAgent', name: 'Main Agent', default: true },
+        ],
+      },
+      channels: {
+        feishu: {
+          enabled: true,
+          accounts: {
+            default: { enabled: true, appId: 'main-app' },
+          },
+        },
+      },
+    });
+
+    const { assignChannelAccountToAgent } = await import('@electron/utils/agent-config');
+
+    await assignChannelAccountToAgent('MainAgent', 'feishu', 'default');
+
+    const config = await readOpenClawJson();
+    expect(config.bindings).toEqual([
+      {
+        agentId: 'MainAgent',
+        match: { channel: 'feishu', accountId: 'default' },
+      },
+    ]);
+  });
+
   it('keeps a single owner for the same channel account', async () => {
     await writeOpenClawJson({
       agents: {
diff --git a/tests/unit/channel-routes.test.ts b/tests/unit/channel-routes.test.ts
index 64e31d576..c43455000 100644
--- a/tests/unit/channel-routes.test.ts
+++ b/tests/unit/channel-routes.test.ts
@@ -102,6 +102,7 @@ describe('handleChannelRoutes', () => {
     listConfiguredChannelAccountsMock.mockReturnValue({});
     listAgentsSnapshotMock.mockResolvedValue({
       agents: [],
+      channelOwners: {},
       channelAccountOwners: {},
     });
     readOpenClawConfigMock.mockResolvedValue({
@@ -367,6 +368,11 @@ describe('handleChannelRoutes', () => {
         accountIds: ['default', 'Legacy_Account'],
       },
     });
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'main', name: 'Main Agent' }],
+      channelOwners: {},
+      channelAccountOwners: {},
+    });
 
     parseJsonBodyMock.mockResolvedValue({
       channelType: 'feishu',
@@ -409,6 +415,353 @@ describe('handleChannelRoutes', () => {
     expect(assignChannelAccountToAgentMock).toHaveBeenCalledWith('main', 'feishu', 'Legacy_Account');
   });
 
+  it('migrates legacy channel-wide fallback before manually binding a non-default account', async () => {
+    listConfiguredChannelAccountsMock.mockReturnValue({
+      telegram: {
+        defaultAccountId: 'default',
+        accountIds: ['default', 'telegram-a1b2c3d4'],
+      },
+    });
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'main', name: 'Main' }, { id: 'code', name: 'Code Agent' }],
+      channelOwners: { telegram: 'main' },
+      channelAccountOwners: {},
+    });
+    readOpenClawConfigMock.mockResolvedValue({
+      bindings: [
+        { agentId: 'main', match: { channel: 'telegram' } },
+      ],
+    });
+    parseJsonBodyMock.mockResolvedValue({
+      channelType: 'telegram',
+      accountId: 'telegram-a1b2c3d4',
+      agentId: 'code',
+    });
+
+    const { handleChannelRoutes } = await import('@electron/api/routes/channels');
+    await handleChannelRoutes(
+      { method: 'PUT' } as IncomingMessage,
+      {} as ServerResponse,
+      new URL('http://127.0.0.1:13210/api/channels/binding'),
+      {
+        gatewayManager: {
+          rpc: vi.fn(),
+          getStatus: () => ({ state: 'running' }),
+          debouncedReload: vi.fn(),
+          debouncedRestart: vi.fn(),
+        },
+      } as never,
+    );
+
+    expect(assignChannelAccountToAgentMock).toHaveBeenNthCalledWith(1, 'main', 'telegram', 'default');
+    expect(clearChannelBindingMock).toHaveBeenCalledWith('telegram');
+    expect(assignChannelAccountToAgentMock).toHaveBeenNthCalledWith(2, 'code', 'telegram', 'telegram-a1b2c3d4');
+  });
+
+  it('does not synthesize a default binding when no legacy channel-wide binding exists', async () => {
+    listConfiguredChannelAccountsMock.mockReturnValue({
+      telegram: {
+        defaultAccountId: 'default',
+        accountIds: ['default', 'telegram-a1b2c3d4'],
+      },
+    });
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'main', name: 'Main' }, { id: 'code', name: 'Code Agent' }],
+      channelOwners: { telegram: 'code' },
+      channelAccountOwners: {
+        'telegram:telegram-a1b2c3d4': 'code',
+      },
+    });
+    readOpenClawConfigMock.mockResolvedValue({
+      bindings: [
+        { agentId: 'code', match: { channel: 'telegram', accountId: 'telegram-a1b2c3d4' } },
+      ],
+    });
+    parseJsonBodyMock.mockResolvedValue({
+      channelType: 'telegram',
+      accountId: 'telegram-b2c3d4e5',
+      agentId: 'code',
+    });
+
+    const { handleChannelRoutes } = await import('@electron/api/routes/channels');
+    await handleChannelRoutes(
+      { method: 'PUT' } as IncomingMessage,
+      {} as ServerResponse,
+      new URL('http://127.0.0.1:13210/api/channels/binding'),
+      {
+        gatewayManager: {
+          rpc: vi.fn(),
+          getStatus: () => ({ state: 'running' }),
+          debouncedReload: vi.fn(),
+          debouncedRestart: vi.fn(),
+        },
+      } as never,
+    );
+
+    expect(clearChannelBindingMock).not.toHaveBeenCalled();
+    expect(assignChannelAccountToAgentMock).toHaveBeenCalledTimes(1);
+    expect(assignChannelAccountToAgentMock).toHaveBeenCalledWith('code', 'telegram', 'telegram-b2c3d4e5');
+  });
+
+  it('preserves mixed-case agent ids when migrating a legacy channel-wide binding', async () => {
+    listConfiguredChannelAccountsMock.mockReturnValue({
+      telegram: {
+        defaultAccountId: 'default',
+        accountIds: ['default', 'telegram-a1b2c3d4'],
+      },
+    });
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'MainAgent', name: 'Main Agent' }, { id: 'code', name: 'Code Agent' }],
+      channelOwners: { telegram: 'mainagent' },
+      channelAccountOwners: {},
+    });
+    readOpenClawConfigMock.mockResolvedValue({
+      bindings: [
+        { agentId: 'MainAgent', match: { channel: 'telegram' } },
+      ],
+    });
+    parseJsonBodyMock.mockResolvedValue({
+      channelType: 'telegram',
+      accountId: 'telegram-a1b2c3d4',
+      agentId: 'code',
+    });
+
+    const { handleChannelRoutes } = await import('@electron/api/routes/channels');
+    await handleChannelRoutes(
+      { method: 'PUT' } as IncomingMessage,
+      {} as ServerResponse,
+      new URL('http://127.0.0.1:13210/api/channels/binding'),
+      {
+        gatewayManager: {
+          rpc: vi.fn(),
+          getStatus: () => ({ state: 'running' }),
+          debouncedReload: vi.fn(),
+          debouncedRestart: vi.fn(),
+        },
+      } as never,
+    );
+
+    expect(assignChannelAccountToAgentMock).toHaveBeenNthCalledWith(1, 'MainAgent', 'telegram', 'default');
+    expect(assignChannelAccountToAgentMock).toHaveBeenNthCalledWith(2, 'code', 'telegram', 'telegram-a1b2c3d4');
+  });
+
+  it('does not mutate legacy bindings when the requested agent does not exist', async () => {
+    listConfiguredChannelAccountsMock.mockReturnValue({
+      telegram: {
+        defaultAccountId: 'default',
+        accountIds: ['default', 'telegram-a1b2c3d4'],
+      },
+    });
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'main', name: 'Main Agent' }],
+      channelOwners: { telegram: 'main' },
+      channelAccountOwners: {},
+    });
+    readOpenClawConfigMock.mockResolvedValue({
+      bindings: [
+        { agentId: 'main', match: { channel: 'telegram' } },
+      ],
+    });
+    parseJsonBodyMock.mockResolvedValue({
+      channelType: 'telegram',
+      accountId: 'telegram-a1b2c3d4',
+      agentId: 'missing-agent',
+    });
+
+    const { handleChannelRoutes } = await import('@electron/api/routes/channels');
+    await handleChannelRoutes(
+      { method: 'PUT' } as IncomingMessage,
+      {} as ServerResponse,
+      new URL('http://127.0.0.1:13210/api/channels/binding'),
+      {
+        gatewayManager: {
+          rpc: vi.fn(),
+          getStatus: () => ({ state: 'running' }),
+          debouncedReload: vi.fn(),
+          debouncedRestart: vi.fn(),
+        },
+      } as never,
+    );
+
+    expect(clearChannelBindingMock).not.toHaveBeenCalled();
+    expect(assignChannelAccountToAgentMock).not.toHaveBeenCalled();
+    expect(sendJsonMock).toHaveBeenCalledWith(
+      expect.anything(),
+      500,
+      expect.objectContaining({
+        success: false,
+        error: expect.stringContaining('Agent "missing-agent" not found'),
+      }),
+    );
+  });
+
+  it('rejects binding requests without accountId before legacy migration runs', async () => {
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'main', name: 'Main Agent' }],
+      channelOwners: {},
+      channelAccountOwners: {},
+    });
+    parseJsonBodyMock.mockResolvedValue({
+      channelType: 'telegram',
+      agentId: 'main',
+    });
+
+    const { handleChannelRoutes } = await import('@electron/api/routes/channels');
+    await handleChannelRoutes(
+      { method: 'PUT' } as IncomingMessage,
+      {} as ServerResponse,
+      new URL('http://127.0.0.1:13210/api/channels/binding'),
+      {
+        gatewayManager: {
+          rpc: vi.fn(),
+          getStatus: () => ({ state: 'running' }),
+          debouncedReload: vi.fn(),
+          debouncedRestart: vi.fn(),
+        },
+      } as never,
+    );
+
+    expect(clearChannelBindingMock).not.toHaveBeenCalled();
+    expect(assignChannelAccountToAgentMock).not.toHaveBeenCalled();
+    expect(sendJsonMock).toHaveBeenCalledWith(
+      expect.anything(),
+      400,
+      expect.objectContaining({
+        success: false,
+        error: 'accountId is required',
+      }),
+    );
+  });
+
+  it('falls back to the legacy owner when explicit default owner is stale', async () => {
+    listConfiguredChannelAccountsMock.mockReturnValue({
+      telegram: {
+        defaultAccountId: 'default',
+        accountIds: ['default', 'telegram-a1b2c3d4'],
+      },
+    });
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'MainAgent', name: 'Main Agent' }, { id: 'code', name: 'Code Agent' }],
+      channelOwners: {},
+      channelAccountOwners: {},
+    });
+    readOpenClawConfigMock.mockResolvedValue({
+      bindings: [
+        { agentId: 'MissingAgent', match: { channel: 'telegram', accountId: 'default' } },
+        { agentId: 'MainAgent', match: { channel: 'telegram' } },
+      ],
+    });
+    parseJsonBodyMock.mockResolvedValue({
+      channelType: 'telegram',
+      accountId: 'telegram-a1b2c3d4',
+      agentId: 'code',
+    });
+
+    const { handleChannelRoutes } = await import('@electron/api/routes/channels');
+    await handleChannelRoutes(
+      { method: 'PUT' } as IncomingMessage,
+      {} as ServerResponse,
+      new URL('http://127.0.0.1:13210/api/channels/binding'),
+      {
+        gatewayManager: {
+          rpc: vi.fn(),
+          getStatus: () => ({ state: 'running' }),
+          debouncedReload: vi.fn(),
+          debouncedRestart: vi.fn(),
+        },
+      } as never,
+    );
+
+    expect(assignChannelAccountToAgentMock).toHaveBeenNthCalledWith(1, 'MainAgent', 'telegram', 'default');
+    expect(assignChannelAccountToAgentMock).toHaveBeenNthCalledWith(2, 'code', 'telegram', 'telegram-a1b2c3d4');
+  });
+
+  it('skips default binding migration when both explicit and legacy owners are stale', async () => {
+    listConfiguredChannelAccountsMock.mockReturnValue({
+      telegram: {
+        defaultAccountId: 'default',
+        accountIds: ['default', 'telegram-a1b2c3d4'],
+      },
+    });
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'code', name: 'Code Agent' }],
+      channelOwners: {},
+      channelAccountOwners: {},
+    });
+    readOpenClawConfigMock.mockResolvedValue({
+      bindings: [
+        { agentId: 'MissingDefault', match: { channel: 'telegram', accountId: 'default' } },
+        { agentId: 'MissingLegacy', match: { channel: 'telegram' } },
+      ],
+    });
+    parseJsonBodyMock.mockResolvedValue({
+      channelType: 'telegram',
+      accountId: 'telegram-a1b2c3d4',
+      agentId: 'code',
+    });
+
+    const { handleChannelRoutes } = await import('@electron/api/routes/channels');
+    await handleChannelRoutes(
+      { method: 'PUT' } as IncomingMessage,
+      {} as ServerResponse,
+      new URL('http://127.0.0.1:13210/api/channels/binding'),
+      {
+        gatewayManager: {
+          rpc: vi.fn(),
+          getStatus: () => ({ state: 'running' }),
+          debouncedReload: vi.fn(),
+          debouncedRestart: vi.fn(),
+        },
+      } as never,
+    );
+
+    expect(clearChannelBindingMock).toHaveBeenCalledWith('telegram');
+    expect(assignChannelAccountToAgentMock).toHaveBeenCalledTimes(1);
+    expect(assignChannelAccountToAgentMock).toHaveBeenCalledWith('code', 'telegram', 'telegram-a1b2c3d4');
+  });
+
+  it('converts legacy channel-wide fallback into an explicit default binding when saving a non-default account', async () => {
+    parseJsonBodyMock.mockResolvedValue({
+      channelType: 'telegram',
+      accountId: 'telegram-a1b2c3d4',
+      config: { botToken: 'token', allowedUsers: '123456' },
+    });
+    listAgentsSnapshotMock.mockResolvedValue({
+      agents: [{ id: 'main', name: 'Main' }],
+      channelOwners: { telegram: 'main' },
+      channelAccountOwners: {},
+    });
+    readOpenClawConfigMock.mockResolvedValue({
+      bindings: [
+        { agentId: 'main', match: { channel: 'telegram' } },
+      ],
+    });
+
+    const { handleChannelRoutes } = await import('@electron/api/routes/channels');
+    await handleChannelRoutes(
+      { method: 'POST' } as IncomingMessage,
+      {} as ServerResponse,
+      new URL('http://127.0.0.1:13210/api/channels/config'),
+      {
+        gatewayManager: {
+          rpc: vi.fn(),
+          getStatus: () => ({ state: 'running' }),
+          debouncedReload: vi.fn(),
+          debouncedRestart: vi.fn(),
+        },
+      } as never,
+    );
+
+    expect(saveChannelConfigMock).toHaveBeenCalledWith(
+      'telegram',
+      { botToken: 'token', allowedUsers: '123456' },
+      'telegram-a1b2c3d4',
+    );
+    expect(assignChannelAccountToAgentMock).toHaveBeenCalledWith('main', 'telegram', 'default');
+    expect(clearChannelBindingMock).toHaveBeenCalledWith('telegram');
+    expect(assignChannelAccountToAgentMock).not.toHaveBeenCalledWith('main', 'telegram', 'telegram-a1b2c3d4');
+  });
+
   it('keeps channel connected when one account is healthy and another errors', async () => {
     listConfiguredChannelsMock.mockResolvedValue(['telegram']);
     listConfiguredChannelAccountsMock.mockResolvedValue({