Solved Horizontal grey lines show up on my screen when increasing resolution.

Hello, i am having a problem with my pc or display. When its put on 1080p resolution everything works perfect, but as soon as i increase the resolution i get grey flash horizontal lines. In games there are no performance issues like fps drops or stuttering but the grey lines appear. I reinstalled all of the drivers that I could, checked the ports and dont know what to do. Its a 4k 60hz TV connected with an hdmi cabel to a RTX 3090 and i really hope its not the graphics card. Could it be a bad HDMI cabel? Maybe i need a better cable for it to display 4k or anything above 1080p. As I said there are no performance issues whatsoever but i dont know what to do anymore. Thanks

I don't have another monitor unfortunately, but it definitely supports higher resolutions. Those horizontal lines showed back up again so I unplugged the HDMI cable and plugged it back in again and the glitching stopped for about 30 seconds and came back again. I guess the cable is the problem then. I will pick up my my old TV from home next week and get a new cable. I’m just hoping that it will resolve the issue. I’ll keep you posted. Thanks for the reply.

Will do.

Looks like it was a faulty HDMI cable. Replaced it with a new one. Thank you for your time.

Oh it was a cheap one for sure! I got 5 meters for 5 dollars or something in that range. Lasted half a year.