Codex desktop chat history repeatedly rolls back and recent messages disappear after app update

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

26.903.71938

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Recent messages in an existing Codex desktop chat repeatedly disappear, and the conversation appears to roll back to an earlier state.

I first noticed this issue on September 9–10, 2026. Messages from September 9 and the morning of September 10 disappeared from an existing chat, although the chat itself remained visible and could still be opened normally.

I continued working in the same chat during the afternoon of September 10. Those new messages were initially visible and Codex successfully created/modified local files during the session.

After Codex updated again on the evening of September 10, the afternoon messages also disappeared. The same conversation is still present in the sidebar, but its recent history has once again been rolled back.

Importantly, files generated or modified by Codex during the missing sessions still exist in the local working folder with the correct timestamps. This confirms that those Codex sessions actually occurred even though the corresponding chat turns are no longer visible.

The affected chat is not in Archived Chats, and changing the chat sorting mode does not restore the missing messages.

I have already submitted in-app feedback from the affected session with diagnostic logs included.

Feedback/session ID: 019f5f63-76af-72b3-8569-745342c36467

What steps can reproduce the bug?

Open an existing long-running Codex desktop chat.
Continue working normally in the chat and send/receive multiple new messages.
Let Codex create or modify files in the local workspace. Confirm that the new chat messages are visible.
Quit/restart or update the Codex desktop app.
Reopen the same chat.
Some or all of the most recent chat turns are missing, and the conversation appears to have reverted to an earlier saved state.
The files created or modified during the missing turns are still present locally.

The issue has occurred more than once for the same chat. It occurred before tonight's update and occurred again after updating Codex on September 10.

At the time I checked the affected conversation, context usage was around 80%.

Feedback/session ID: 019f5f63-76af-72b3-8569-745342c36467

What is the expected behavior?

All previously completed chat turns should remain available after restarting or updating the Codex desktop app.

Updating, restarting, sorting, or reopening a conversation should not cause recent messages to disappear or make the conversation revert to an older state.

If newer messages are stored server-side, the Codex app should synchronize and display the latest conversation state rather than showing an older snapshot.

Additional information

This has now happened repeatedly to the same long-running chat.

Timeline (UTC+8 / China Standard Time):

Sep 9–10: recent messages from Sep 9 and the morning of Sep 10 disappeared.
Sep 10 afternoon: I continued working in the same affected chat and new messages were visible normally.
Sep 10 evening: Codex was updated. After the update, the afternoon chat history also disappeared.

The Codex version I was using earlier on Sep 10 was:
26.903.61454

Current version after the Sep 10 evening update:
[PASTE CURRENT VERSION HERE]

Other checks already performed:

The affected conversation is still visible and can be opened from the sidebar.
It is not present under Archived Chats.
Chat sorting was already set to Recent; changing sorting modes did not restore the missing turns.
Local files generated during the missing sessions still exist with their correct timestamps.
In-app feedback was submitted with diagnostic logs.
Feedback/session ID: 019f5f63-76af-72b3-8569-745342c36467
I have requested an OpenAI account data export and am waiting to verify whether the missing Sep 9–10 turns are present in the exported account data.

I did not intentionally delete this conversation or use “Delete all chats”.

Start with the supplied Windows reproduction and the diagnostic logs from feedback/session ID 019f5f63-76af-72b3-8569-745342c36467. Investigate chat persistence and synchronization across restart or app update, using the repeated rollback timeline as the test scenario. Done means completed turns remain visible after reopening the chat while locally modified files remain intact.