[macOS][Fullscreen Space] Chinese Pinyin IME candidate window is invisible in the Option+Space chat overlay

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

Version 26.707.91948

What subscription do you have?

100$ pro

What platform is your computer?

Darwin 25.5.0 arm64 arm

What issue are you seeing?

The candidate window for Apple’s built-in Simplified Chinese Pinyin input method is invisible in the Option+Space chat overlay when it is opened over an application running in native macOS full-screen mode.

The Pinyin composition text is displayed correctly with a blue underline, and the input method remains functional internally. Pressing the arrow keys and Return, or pressing number keys such as 1, 2, and 3, selects different Chinese candidates. However, the candidate window itself is not visible anywhere on the screen.

The issue is specifically related to native macOS full-screen Spaces:

• When VS Code is in native macOS full-screen mode and the chat overlay is opened with Option+Space, the candidate window is invisible.

• When VS Code is not in full-screen mode, the candidate window appears normally in the same chat overlay.

• The issue occurs with Apple’s built-in Simplified Chinese Pinyin input source, not a third-party input method.

• There is no error message.

This suggests that candidate generation and keyboard selection still work, but the macOS IME candidate window is hidden, clipped, or placed behind another window in the full-screen Space.

What steps can reproduce the bug?

Feedback ID: no-active-thread-019f69a8-c0c4-7a62-805a-114fdab9470c

What is the expected behavior?

The macOS Chinese Pinyin candidate window should remain visible near the text cursor when typing in the Option+Space chat overlay, regardless of whether the underlying application is in normal windowed mode or a native macOS full-screen Space.

Full-screen mode should not affect the visibility, positioning, or window level of the system IME candidate panel.

Additional information

Environment:

• Codex/ChatGPT app version: 26.707.91948
• macOS version: 26.5.2
• Kernel/platform: Darwin 25.5.0 arm64 arm
• Device: MacBook Air with Apple M5
• Input method: Apple built-in Simplified Chinese Pinyin
• Trigger: Option+Space chat overlay opened inside a native macOS full-screen Space
• Normal windowed mode: candidate window is visible
• Native full-screen mode: candidate window is invisible
• Candidate selection using number and arrow keys still works