The code editor is available in template editing mode but only shows the post content

[carolinan]

Description

The code editor is available when editing a template in the template editor (accessed from the block editor).
The code editor shows the post content and the post title and nothing else -even if both blocks are removed from the template.

-I thought the code editor was not yet supported and that it was meant to be disabled both in template editing and the site editor.

Step-by-step reproduction instructions

1. Activate a theme with support for template editing
2. Go to the block editor.
3. Create a new template.
4. When inside the template editor, select Options -Code editor
5. Compare the code in the code editor with the actual template.

Screenshots, screen recording, code snippet

No response

Environment info

WordPress 5.9-beta2-52361 via the beta tester plugin
With and without Gutenberg current trunk.

For the theme, I usedTwenty Twenty-Two and a classic PHP-based theme, underscores (_s), and added support for template editing.

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

No

[Mamaduka]

That's correct. FSE currently doesn't support Code Editor mode, and we should probably disable it in Template Editing Mode since it doesn't work correctly.