Ok, so have you just recently updated to the latest 6.8 kernel that Zorin made available? If so, that could very well be a cause of this issue. If you can run:
- uname -r
in a terminal, that would tell you what kernel version you're currently running.
Also, if you do happen to be on the latest 6.8 kernel, I believe it's been discovered that version 545 of the Nvidia drivers don't work well with them, and an update to 550 would be required (someone with more nvidia experience could chime in here).
First steps would be to make sure we know what kernel you're running.
EDIT: After update, display is really slow and screen is tearing - #6 by AZorin