When I stay in a game for too long the game screen starts flickering in random pixels on my screen. Not sure if it's a graphical issue or the game graphics causing this to happen.

When I Fullscreen/Un Fullscreen it will reset back to normal. 
My pc is running on these components:
Operating system: Windows 11 Pro 64-bit (1.0, Build 26100)
System Manufacturer: Lenovo
Processor: Intel(R) Core(TM) i5-8400T CPU @ 1.70GHz
Memory: 12.288 GB RAM
DirectX Version: DirectX 12

My game runs at 200fps+ and settings on max.
I try messing around with the settings still can't figure out what's causing it.