It might help if you uploaded an image directly from your computer, rather than a photo of your monitor. But I can just make out some little squares. I’ve never seen those myself, but I have seen some examples that were far more obvious than this. I don’t know what the cause was.
It’s possible a driver change would help, but in that event I would consider going to a newer one rather than revert to an older one. But trying both is also find, and lets you get some comparison data.