If you can capture it with screenshots or recording software it totally eliminates chances of monitor or cable being faulty.
Though of course, you'd have to send those screenshots/videos to another PC/upload them to youtube because your monitor could display the recorded content badly as well
Yeah, that would be stupid to do, hahahaha!
I found the manual of the monitor and it says that if you encounter blurred screen, blurred letters, screen flicker or tilted screen you should use the auto/set button.
What I am thinking is that somehow, even tho I play every game in monitors native res, it switched resolution or something for a second and then it blurred and started to waver my display.