GPT-5.6 Sol unexpectedly reverted all uncommitted changes across sessions in the same workspace

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

Codex Desktop 26.707.31428

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Darwin 27.0.0 arm64 arm

What issue are you seeing?

Summary

When using the GPT-5.6 Sol model, all files modified during development were unexpectedly reverted after the task completed.

What happened

After GPT-5.6 Sol finished applying its changes, every modified file was reverted to its previous state.

I first suspected that this was caused by Git, but after checking the Git history, I confirmed that no Git operation (such as checkout, reset, restore, or revert) had occurred. The reversion did not originate from Git.

What was actually reverted was every uncommitted change in:

• the current session where GPT-5.6 Sol was used, and
• every other session in the same workspace that had also used GPT-5.6 Sol.

I have not yet been able to determine what triggered this behavior.

Investigation

After the incident, I reviewed the logs of several affected sessions.

I found that the logs still contained the complete file modification history and the generated content. In other words, the generated changes were not lost from the session logs—they were only removed from the working directory.

Using those logs, I spent nearly 15 hours manually restoring all of the reverted files.

Expected behavior

GPT-5.6 Sol should never revert unrelated uncommitted changes across sessions or remove completed modifications from the working directory.

Additional information

• This issue has only occurred with GPT-5.6 Sol.
• I have used other Codex models extensively in the same workspace, and none of them have exhibited this behavior.
• The issue appears to affect the entire workspace rather than only the active session.
• No Git history was changed, which suggests the revert happened outside of Git.

<img width="457" height="459" alt="Image" src="https://github.com/user-attachments/assets/24555f96-2e3c-4a1b-96b6-03b43d0b8ecf" />

What steps can reproduce the bug?

Reproduction

Unfortunately, I have not been able to reproduce this issue consistently.

This happened only once while using GPT-5.6 Sol in a workspace with multiple Codex sessions.

The sequence was approximately:

1. Open multiple Codex sessions in the same workspace.
2. Use GPT-5.6 Sol to modify multiple files.
3. Let the model finish applying its changes.
4. Some time after the task completed, all uncommitted modifications in the affected workspace were unexpectedly reverted.

The revert was not initiated by any Git command. I verified that no git reset, git restore, git checkout, or other Git operation had occurred.

Because I have not been able to reproduce it again, I cannot provide a minimal reproduction case. However, I still have the affected session logs, which preserved the generated edits even though the working directory was reverted.

What is the expected behavior?

GPT-5.6 Sol should only apply the requested file modifications and should never revert unrelated uncommitted changes.

Specifically:

• Existing uncommitted changes should remain intact.
• Changes from other sessions in the same workspace should not be affected.
• No files should be reverted unless an explicit Git operation or a user-confirmed rollback is performed.

Additional information

_No response_