Display Problem when painting on Clipping Mask

[PetrichorCrown]

Hi, 

Mid-drawing session while painting on a clipping mask for shadows, my strokes would be covered with this pixelated, flat colored block. This is purely on the canvas display and when I flip the canvas it disappears and reveals the brush strokes but as you can imagine - very frustrating.

I've tried restarting the program, updating drivers and restarting my PC with no success. Many thanks for your help

[kevin stohlmeyer]

@PetrichorCrown definitely looks like a GPU issue. Go to Photoshop Help Menu/System Info and copy/paste the results in a reply.