Question What is wrong with my gpu

[core2314567]

So I have an xfx rx570 8gb and it's been making weird lines and crashing so I changed windows didn't help then it stopped so I thought good then today it came back again and I can't open games without it crashing In like 10secs so I did heaven benchmark for half an hour and no issues so it's not the gpu but then what is Wrong I have a xenon e5 2680 v4 16gigs of ddr4 ram and rx 570 I mentioned I have an hpz440 700w psu

 

[Dylanx3849]

So I have an rx570 and I got it a week ago and it's been making weird lines and crashing so I thought the gpu was bad so I did a benchmark on heaven for HALF AN HOUR and nothing happened so I thought the gpu is fine then I open a game and it does it again then the next few days it was working fine