Recently, my monitor has been glitching out to the extent it's unusable. A few months ago it started with a few glitched lines (which disappeared when I redirected my room fan to it, which is quite odd considering I monitored the temperatures a lot throughout that period of time and nothing was overheating). Worth noting that changing to any other resolution/refresh rates would cause extreme glitching. It was also glitch out on startup, which makes me believe it's a monitor issue.
Following this I changed the given HDMI 2.0 cable to a DP 1.2, and for a while up until yesterday, worked fine with no issues, except for a discolored line at the bottom, and the top part being weird, but still very hard to notice.
Woke up this morning, and all of a sudden my monitor turned much more glitchy than it did months ago, not only that it started consistently freezing on the bottom 2/3rds of the monitor. (see above)
Does anyone know the source of the problem? I used to think it was the monitor but now I'm not so sure. And if possible, is there a fix?
[Edited the thread to add issue detail]