Help please! Screen goes black randomly

[chancedaraptor]

So I installed an RTX 3070 ti a few days ago and it's working great. But maybe like once an hour or so my main monitor (I have a dual monitor setup) will just go black for about a second or 2. All the cables are firmly connected, and all the drivers are updated. The only thing I can think of is maybe the GPU is damaged? I had a bit of a hard time installing it. But I removed it and inspected it and it's completely fine. I even tried installing it in the other PCIE slot cause I was worried the first one might be damaged and the same thing is still happening. I switched out the DP cables and still no luck. When I installed it I noticed there was some sagging happening since the GPU is pretty heavy. So I bought a stand for it and that took care of the sagging issue but still, the same problem is happening. Also, last night when playing League of Legends a sort of "black line" appeared on the upper left part of my monitor. It was very transparent but definitely noticeable. I restarted my PC and it never came back not sure if that has something to do with this. GPU temps are normal and my PC is quiet as a mouse even when playing games. The only other thing I can think of is in the display settings my PC recommends I have my monitor resolution be at 3840 x 2160 but I prefer it at 2560x 1440 so keep it like that. Any other ideas why this would be happening?

PC Specs (Windows 11)

-12th Gen Intel(R) Core(TM) i7-12700KF 3.61 GHz

-32gb ram

-RTX 3070 ti

-Motherboard is PRO Z690-P DDR4 (MS 7D36)