Thanks for the report. I was also able to reproduce this problem.

Also, while looking for a solution, I discovered an issue with inconsistent command actions, and issues with the Site Editor.

In the Post Editor, there is only one action: "Toggle code editor".

In the Site Editor, on the other hand, the commands change depending on the editor context.

Furthermore, in the Site Editor, the hook that disables the editor type does not seem to be applied.

function disable_code_editor( $settings, $context ) {
	$settings['codeEditingEnabled'] = false;
	return $settings;
}
add_filter( 'block_editor_settings_all', 'disable_code_editor' , 10, 2 );

Therefore, in order to comprehensively resolve this issue, I think we will probably need to follow the steps below.

• Improve command consistency in the Post Editor and the Site Editor:
  • Minor command tweaks #58148
• Ensure that codeEditingEnabled and richEditingEnabled block editor settings are correctly applied to the Site Editor as well.
• When codeEditingEnabled or richEditingEnabled is false, disable command actions for it.
  • Command Palette: Prevent mode switching if only one editor mode is available #59299

Update:

In the Post Editor, there is only one action: "Toggle code editor".
In the Site Editor, on the other hand, the commands change depending on the editor context.

This issue was resolved by #58148. It seems that it has been unified to Open code editor/Exit code editor.

Update: In #59299, switching modes via the command palette is now disabled when only one editor mode is available.

Hey! Is this issue is valid?

Ensure that codeEditingEnabled and richEditingEnabled block editor settings are correctly applied to the Site Editor as well.

Seems unrelated to this package maybe and should be a separate issue.