macOS Codex app fullscreen button does not work, but fullscreen keyboard shortcut does

What issue are you seeing?

On the macOS Codex desktop app, the window fullscreen button does not enter fullscreen mode, but the standard macOS fullscreen keyboard shortcut does work.

This makes the issue appear specific to the window button / titlebar control handling rather than fullscreen support generally.

Steps to reproduce

1. Open the Codex desktop app on macOS.
2. Click the macOS fullscreen button in the window titlebar / traffic-light controls.
3. Observe that the app does not enter fullscreen mode.
4. Use the macOS fullscreen keyboard shortcut, Control + Command + F.
5. Observe that the app enters fullscreen mode successfully.

Expected behavior

Clicking the macOS fullscreen button should enter fullscreen mode, the same as the keyboard shortcut.

Actual behavior

The fullscreen button does not work, but the keyboard shortcut does.

Environment

• App: Codex desktop app for macOS
• macOS version: not provided
• Codex app version: not provided
• Reproducibility: observed by user; exact repro frequency not yet provided

Additional notes

This may be related to recent desktop window/titlebar handling changes, but it is distinct from a general inability to enter fullscreen because the keyboard shortcut still works.