Mac desktop app maintains a different conversation history than web and iOS

What version of the Codex App are you using (From “About Codex” dialog)?

26.727.51351

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Darwin Sadies-MacBook-Neo.local 25.5.0 Darwin Kernel Version 25.5.0: Mon Apr 27 20:41:22 PDT 2026; root:xnu-12377.121.6~2/RELEASE_ARM64_T8140 arm64

What issue are you seeing?

I initially discovered this because a conversation created on the Mac desktop app did not appear on the web or iPhone even after several days, while new conversations on the web and iPhone remained synchronized.

<img width="1268" height="682" alt="Image" src="https://github.com/user-attachments/assets/4c4bd87f-8b5d-4895-a574-e77adf5fc19b" />

The ChatGPT/Codex Mac desktop app has a different conversation history than chatgpt.com and the iOS app.

The browser and iPhone remain synchronized with each other, but the desktop app shows a separate set of conversations, including chats that never appear on the web or mobile.

Projects appear to sync correctly. Conversation history does not.

Troubleshooting already performed:

Verified same account.
Reinstalled the desktop app.
Logged out and back in.
Browser history matches iPhone.
Renamed ~/Library/Application Support/com.openai.chat.
Renamed ~/Library/Application Support/OpenAI.
None of the above changed the behavior.

Environment:

macOS Tahoe 26.6
App version 26.727.51351
ChatGPT Plus
iPhone iOS 26.5

Expected behavior:
The desktop app should show the same conversation history as chatgpt.com and the iOS app.

What steps can reproduce the bug?

Feedback ID: no-active-thread-019fc390-6c8a-7681-8581-d204f0cb2083

What is the expected behavior?

The ChatGPT Mac desktop app should display the same conversation history as chatgpt.com and the iOS app when signed into the same account. New conversations and updates should sync across all platforms within seconds or minutes, not days. Projects and conversations should remain consistent across devices.

Additional information

Additional information:

The issue has been occurring consistently for weeks, not just once.
ChatGPT on iPhone and chatgpt.com always remain synchronized with each other.
Only the Mac desktop app diverges.
Projects synchronize correctly across all devices, but conversation history does not.
I initially noticed the problem because a meal-planning conversation created on the Mac never appeared on my iPhone after driving home (~5–10 minutes later). I later realized some conversations created on the Mac never appear on the web or iPhone, even after several days.
I backed up important Mac-only conversations before troubleshooting because they contained work that did not exist on any other device.
Troubleshooting performed:
Verified same account.
Logged out/in.
Reinstalled the app.
Confirmed browser and iPhone match each other.
Renamed ~/Library/Application Support/com.openai.chat.
Renamed ~/Library/Application Support/OpenAI.
None of these steps changed the behavior.

<img width="388" height="698" alt="Image" src="https://github.com/user-attachments/assets/5f4a7e7d-48b8-4e52-903f-1e254079a4db" />