Background is glitching

Sorry I cannot use Github because it’s one of the filtered sites in my web blocking.


I’ve been facing this issue since yesterday or the day before yesterday, the background looks weirded out. I think I have also seen a blue color. This does not happen on my other computer, and my other computer has really bad specs so I would expect issues there and not on this gaming laptop from 2019.
Firefox browser.
I tried clearing cookies for this site, restarting PC, clearing ‘‘cached web content’’. No effect. I currently cannot try other browsers due to my blocking rules but I am really surprised this happens with something that does not run as a program on my pc but * noob terms* gets loaded from the internet.
It’s pretty much unplayable right now, it’s awfully ugly to look at.
I would really appreciate any help here