Codex cannot edit file. Claims its read only when its set to Full Access

What version of Codex is running?

0.77.0

What subscription do you have?

Plus

Which model were you using?

gpt-5.2-codex

What platform is your computer?

Microsoft Windows NT 10.0.19045.0 x64

What issue are you seeing?

<img width="1068" height="362" alt="Image" src="https://github.com/user-attachments/assets/e953ea3f-28c6-432e-859d-509856b2d0be" />

<img width="366" height="344" alt="Image" src="https://github.com/user-attachments/assets/7a6e1d78-ce0c-4b31-a618-3a47aede961f" />

What steps can reproduce the bug?

Start Codex and set sandbox_mode = "workspace-write" (or sandbox = "workspace-write", its changes nothing) and you see, that Codex still read-only

What is the expected behavior?

_No response_

Additional information

_No response_