[macOS][Chat] Desktop app goes offline; valid conversations fail to load while iOS works #49170

Summary

The unified ChatGPT desktop app on macOS is intermittently becoming unusable in the Chat surface while the same account and conversations continue to work normally in the ChatGPT iOS app.

The failure presents as a mix of connection, account-state, and conversation-loading problems in the desktop app.

Subscription

• ChatGPT Plus

Platform

• macOS desktop app
• Apple Silicon Mac
• Same account simultaneously tested in ChatGPT iOS
• Network retested over 5G / phone hotspot

Actual behavior

During the incident on 2026-09-29 JST, the macOS desktop app showed several recurring symptoms:

• Bottom-left status changed to Offline even though the Mac had working internet access.
• The account/profile UI partially lost its normal state/appearance.
• Recent chats and project contents sometimes disappeared or failed to populate.
• Existing conversations remained visible in the sidebar, but opening one showed:
  • “Could not load this ChatGPT conversation” / Japanese equivalent: 「このChatGPTの会話を読み込めませんでした」.
• New messages could be typed into the composer but sending did not progress.
• The app sometimes became fully unresponsive / frozen.
• Reconnection/loading spinners appeared repeatedly.
• Codex functionality could still work at times while the ordinary ChatGPT Chat surface was broken.

Cross-client comparison

At the same time, the ChatGPT iOS app on the same account could open and continue the exact same conversation normally.

This strongly suggests the conversation still exists server-side and the account itself is valid; the failure appears specific to the macOS desktop client or its desktop session/synchronization path.

Troubleshooting already attempted

• Fully quit and relaunched the desktop app 4 times.
• Switched/tested network connectivity using 5G / phone hotspot.
• Confirmed the iOS app remained functional on the same account and could access the same conversation.
• Confirmed the desktop app could sometimes repopulate the sidebar after relaunch, but selecting the conversation still failed to load it.

The problem recurred after relaunches.

Reproduction pattern

The issue is intermittent, but the observed sequence was roughly:

1. Use ChatGPT/Codex desktop normally.
2. Desktop enters a reconnecting/offline state.
3. Relaunch the app.
4. Sidebar/account UI may partially recover.
5. Select a known-good ChatGPT conversation that is currently open and usable on iOS.
6. Desktop displays “Could not load this ChatGPT conversation.”
7. Attempts to start/send a new chat may also stall.
8. The desktop app may freeze or return to an offline/reconnecting state.

Expected behavior

• If the Mac has working internet access, the desktop app should not enter a persistent false-offline state.
• Account/profile UI should remain synchronized.
• A conversation that is valid and currently usable on iOS should open normally on macOS desktop.
• New messages should send normally.
• The app should recover cleanly from transient reconnects without repeated relaunches.

Additional notes

This does not appear to be a deleted/ghost-conversation case: the same conversation remains valid and actively usable on iOS while the macOS desktop app reports that it cannot load it.

Screenshots captured during the incident show:

• the desktop app explicitly displaying Offline;
• the same valid conversation present in Recents but failing with “Could not load this ChatGPT conversation”;
• partial account/profile UI state during the failure.

I can provide additional sanitized diagnostics if maintainers need them.