Photoshop breaks if I try to use my graphics card. (Grey boxes appear, image preview issues, etc)

This is an issue across all(?) latest versions of Photoshop on Mac and PC. I've been running into major GPU-related issues on my Mac Pro 2013, where images would load up incorrectly tiled, boxes would appear when painting, the view would freeze, and eventually got to the point where I couldn't even see my files anymore when I opened them. I had to bypass my GPU entirely to even see what was going on.

Thinking that my graphics card was out of date and incompatible, I built a new PC using Windows 10 to make sure I wouldn't have hardware limitations. A huge investment and a few days later, and I'm experiencing the same persistent problems, and the latest versions of photoshop (from 24.2-25.5) will ONLY run if I deselect "use GPU".

HOW/WHEN IT HAPPENS:
The issue usually makes itself known when I paint on a Levels Layer mask, which sits underneath a grey layer set to "color" mode. Instead of seeing the brush, I get a series of grey boxes (attached). Changing the zoom level also renders a chunk of the canvas with a grey box overtop. This is just one of a few problems I've been running into, which include flickering/white flashing, boxes around the cursor when hovering over menus, the canvas freezing, and the cursor changing back to a pointer and ignoring the tool settings & not showing any changes when clicking/brushing.

I've been troubleshooting this for three days now and am seriously behind on work as a result.

WHAT I'VE TRIED:

• Uninstalling & Reinstalling wacom drivers, trying older versions instead of the newest ones.
• Uninstalling & Reinstalling NVIDIA graphics drivers, using older versions, alternating between studio and game mode
• Resetting PS preferences, changing all combinations of the following:
  • Turning off Multithreaded compositing
  • Turning off "Use OpenCL"
  • Disabling native canvas
  • Using older GPU mode
• Using older versions of Photoshop. Currently PS21 (22.2) is the least glitchy one to use.

I've been using Photoshop since I was a kid and I've never been more upset, frustrated, and disappointed with how broken this program is - these display issues have been persistent but small over the last couple years but now they are rendering the program unsuable. Why did I just drop a few hundred bucks on a graphics card that the current versions of Photoshop can't even use?