RTX 3070 TUF Black screen when gaming

Hi everyone! Some months ago I got a RTX 3070 TUF, and I realized that when I am playing anything with high graphics, fans go 100%, and I usually get a black screen after some minutes....

Probably is temp related, and Im on my way to repaste both GPU and CPU, but I have a question; when I run a stress test or benchmark, I doesn't happen, so why?

TIA!