Rtx 3060 give black screen under load and acts normal after a few minutes and random green screen

I purchased an evga rtx 3060 but sometimes it gives green artifacts on bios and windows I ran mods/mats 455.127 and it passed all the tests when the processor igpu is used as the display output but gives the black screen when test is run with the rtx card as the display output. It also gives a temporary black screen when running unigine and furmark but run both test normally after. I haven't taken it apart yet but does anyone have any ideas what the problem could be. My PSU is a new Corsair AX 850 Gold. I know mods/mats rules out vram problems and the Nvidia driver installing correctly rules out bios issues