The first thing I would check is that you have the correct drivers for the AMD Graphics card.
Are you using Open Source or Proprietary driver?
Sometimes running low on RAM can cause this. It looks like you have 8 gigs - which should be more than enough- might be worth testing for Memory Leaks or increasing swap.
Finally, this problem seems more common in Gnome / Gnome-shell. You may opt to reinstall the shell
sudo apt install --reinstall gnome-shell
sudo apt install --reinstall zorin-os-desktop