Vietnamese input error with OpenKey in Codex CLI from version 0.27.0

What version of Codex is running?

0.29.0

Which model were you using?

gpt-5

What platform is your computer?

Darwin 24.6.0 arm64 arm

What steps can reproduce the bug?

1. Set OpenKey as the default input method.
2. Open the terminal and run codex to enter the CLI.
3. Type the word hiển.
4. Result: the CLI displays "iiheen" instead of "hiển".

What is the expected behavior?

Codex CLI should properly handle Unicode Vietnamese characters entered via OpenKey.
Version 0.25.0 worked

What do you see instead?

_No response_

Additional information

_No response_