BUG: Chat deletions do not sync between Desktop and Mobile, leaving stale/ghost conversations

Summary

Chat deletions do not synchronize between the desktop and mobile chat lists. When a chat is deleted in the mobile app, it remains visible on desktop even after restarting the desktop app. The reverse direction is also affected: deleting a chat on desktop leaves it visible on mobile.

Steps to reproduce

1. Open the same account on desktop and mobile and locate a chat visible in both chat lists.
2. Delete the chat in the mobile app.
3. Check the desktop chat list: the deleted chat remains visible.
4. Close and restart the desktop app, then check again: the stale entry is still present.
5. For another chat visible on both devices, delete it on desktop.
6. Check the mobile chat list: that deleted chat remains visible there as well.

These steps describe the user's reported observations; no additional conversations were deleted to prepare this report.

Expected behavior

Deleting a chat on one device should propagate to the other clients for the same account and remove it from their chat lists. Restarting the desktop app should reconcile the list with the current state.

Actual behavior

The other client retains stale/ghost conversations in its chat menu. The issue occurs in both directions (Mobile → Desktop and Desktop → Mobile). Restarting the desktop app does not resolve it.

Impact

The chat lists become inconsistent across devices, making cleanup unreliable and leaving users uncertain whether a deletion succeeded. This undermines trust in conversation management and data controls.

This report concerns visible chat-list synchronization. It does not establish the backend deletion status, a data leak, or the underlying cause.

Troubleshooting already attempted

Restarting the desktop app did not remove the stale entries.

Environment

• Affected surfaces: desktop chat list and mobile chat list
• Exact desktop/mobile app versions, mobile OS, subscription, occurrence timestamps and affected conversation IDs: not supplied
• No private conversation content or account identifiers are included

Related issue / scope

Related account-management report: #46232 (missing Delete action for Work conversations). This is a separate bug: here the Delete action is available and used, but its result does not synchronize across clients.

Please investigate cross-device chat-list synchronization and stale-entry reconciliation, including after a desktop restart.

No file, test, or entry point is named in the report. Start by tracing the desktop and mobile chat-list synchronization and restart reconciliation paths; done means a deletion on either client removes the conversation from the other client's list, including after desktop restart, with coverage for both directions.