On QogirBudgie theme and several others I get this:
While for example on Arc theme I get this:
Any ideas what is going on and how I can fix it?
You have the snap version of gnome-software installed.
It’s a well known and annoying bug with the snap … it only works with a few themes in the gtk common theme snap
We are waiting for the rollout of theme support for snaps which is due soon ish.
In the interim you can remove the snap and install the gnome-software package
Or…
If your theme of choice is available as a snap, you can « connect » it to the snap-version of software app.
and after installing this ↑ you open a terminal and :
sudo snap connect snapstore:gtk-3-themes qogir-themes:gtk-3-themes
…maybe it’s not snapstore but gnome-software, see what fits with :
snap list
See also :