Description

When creating a sticky header on a page template in TT5, I have to create a group around the header template part and change the position setting to sticky. If I then edit a page that uses this page template from the site editor, the additional group of the header is not displayed in the list view. It does work on the frontend and on the backend in the page edit though. The code is correct, it's only the group that is missing from the list view to identify there's a different setup in the header. This is confusing to users as they can't find where the sticky setting is set, as the group is not showing in the page edit view.

Step-by-step reproduction instructions

1. Have a clean install of WP 6.7, no Gutenberg plugin needed
2. In the site editor, go to the default Pages template
3. Make the header sticky by putting the header template part into a group and set that group to "Position: sticky"
4. For better visibility, change the background color of the group to another color
5. Save the Pages template
6. Still in the site editor, navigate to the pages selection and select the Sample Page or any other page
7. Open the list view if it's not open already and confirm the header template shows on the top level, but the sticky header does work in the editing area
8. Confirm the sticky header also works on the frontend

Screenshots, screen recording, code snippet

Environment info

• WordPress 6.7
• Twenty Twenty-Five
• Nothing else installed/acitve

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

• Yes

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

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure