Cache is preventing that edited themes render as expected

[matiasbenedetto]

What?

When the user makes changes to a theme and save the changes using CBT in platforms using WP_Cache, the editor and the site frontend could fail to render the site because of the cache.

How to reproduce

1. Create a WordPress site in a platform using Object cache (example: Pressable).
2. Install Create Block Theme plugin.
3. Open the site editor, change the title of the default theme, and save the changes.
4. Go to CBT sidebar and click 'Save theme changes'.
5. The editor page will refresh, and you will see a blank page.

Screencast

This screencast reproduces the issue and also shows how to fix it manually flushing the sites cache.

Screencast.from.29-05-24.21.22.38.webm