Strange glitching - new pc or new PS version?

I'll be so relieved if anyone knows the solution to this annoying problem!

I just upgraded my Windows PC, and now Photoshop has been running heaps better in terms of startup, process speed and no more scratch disk errors.

However, a new problem has emerged that might not be the end of the world, but it is bugging me and it shouldn't be happening.  I don't know if it is the new PC, or the new version of PS that has now installed.  Maybe i'm just missing a simple setting in preferences somewhere?

Hopefully the video will show it.   Essentially, a huge block of colour appears when i'm either editing text, zooming in and out etc.  It sometimes shows as a duplicate of another layer on the design.
**In this example, i'm designing a cosmetics label.... The gradient from the text i'm editing spread across and it also showed a duplication of text from another layer to the left.

Possible relevant info:
Since setting up the new pc, PS is now running version 25.1.0
I have tried the toggle for the Graphic Processor in PS Preferences (no change)
I have checked graphics/display drivers and they're all up to date