Model does now know it is in plan mode after fork

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

26.325.31654 (1272)

What subscription do you have?

Plus

What platform is your computer?

Darwin 25.3.0 arm64 arm

What issue are you seeing?

it tries everything to code in the plan mode

<img width="692" height="338" alt="Image" src="https://github.com/user-attachments/assets/0ac324be-8043-4ed2-b452-91c1fa1d199d" />

What steps can reproduce the bug?

1. Start a thread in a worktree
2. Plan mode and let the thread generate a plan
3. Let it implement the plan
4. git checkout . all the code and fork back after the plan
5. Switch back to plan mode
6. ask model "Are you in plan mode?" and it says no. It cannot generate a plan , it tries to code in plan mode.

What is the expected behavior?

_No response_

Additional information

019d6738-8f4f-7ff0-8161-e7a80a4fc11c