Might have found the solution; I underclocked my gpu from 1040 to 1000 and also increased the power limit by 10%; I ran the benchmark again. ATM all good. I don't know how and why this works, tho. Needs some more testing.
Well,
This "condition" started a while ago (maybe a year) but recently it started to be outrageous and unbearable.
While playing R6 , it suddenly turns into a black screen and the sound james. From that point on, I have to press the power button and restart it, and than all goes back to normal...