Desktop switcher doesn't show background

[Giacomod]

I recently upgraded to W11 and now whenever I want to switch desktops, or create new ones, my background does not show up on the desktop switcher. It doesn't affect my workflow, just my OCD. Is there a way of fixing this?

[#2]

Seconding this, I first encountered the problem after cleaning the "Thumbnails" cache with the official Windows "Disk Cleanup" utility.

However, I am unable to get Windows to update the cache, even after changing the background image several times:

A screenshot of the Desktop Switcher showing two desktops with missing wallpapers.

Does anyone know a method to force Windows to re-generate the thumbcache?