Gnome themes don't work in Ubuntu 20.04 Focal

Hi all,
From near 10 days I have problems with gnome themes. Maily with the apps themes.
The problems is that as i choos a theme from my gnome-tweaks the resulting image reports abnormal dimensions in the icons and the dimension of bars. I don’t understand why. I’m sure that most of these themes worked well first, even the default theme Adwaita is deformed.
I’ve tried to uninstall and reinstall gnome-tweaks but the issue is the same.
[sudo apt-get remove --purge gnome-tweaks && sudo apt-get install gnome-tweaks].
Note: I only download themes from and the Official ubuntu repositoties.

I have this problem also and what I found was my Laptop uses Nvidia 1650ti and the problem is in the GPU drivers. If I use my intel video drivers it’s fine. May not be your problem at all but it’s worth looking into. Please keep this thread going if you find a solution that works I could use that info too. Good Luck.

Any solution?

No until now. Anyway if the problem depends on a Nvidia driver as Charlie suggests It’s better that I call my computer consultant.

My consultant has suggested me the correct solution: it was a GTK issue. Firstly, i’ve used the following command:
sudo apt-get install --reinstall libgtk-3-common gtk3.0
Except some themed like AzenisIcons (too big) the others now work.
I hope this is a useful tip.

Icon theme broken or gk. Reinstall gtk and use another icon theme. Do see these bugs sometimes too