Custom Prompts Drop Additional Message Text

What version of Codex is running?

codex-cli 0.81.0

What subscription do you have?

pro

Which model were you using?

any

What platform is your computer?

Darwin

What terminal emulator and version are you using (if applicable)?

Cursor Terminal

What issue are you seeing?

Custom prompt commands drop additional messages.

`/prompt:mycustomprompt additional tips`

The addtional tips get dropped. This is very frustrating.

What steps can reproduce the bug?

This should always reproduce. Just try a custom command and then tab it to complete in message window and then add additional prompt text

What is the expected behavior?

The additional text should be appended after the custom prompt.

Additional information

This works fine in both Cursor cli agent and Claude code cli agent. Please add! It is a very common for me to use custom prompts with additional notes.