UPDATE.
After running the card for 2 months i have some notes to make. After the flash of the stock bios the card run like a charm, no weird artifacts in google chrome anymore. One day after reaching power limit in a game i was tempted to raise the power limit vie msi afterburner. After i did that the artifacts in google chrome reappeared(no weird behavior anywhere else). i chouldnt find a way to make them stop for a week, ofcourse i imidiatly turned down then power limit. I started thinking that this probably was a softwear issue all along and propabl had to do with google chrome miss behaving with AMD drivers (i still run the drivers i had 2 months ago when i first got the card 18.5.1).One day a windows update pop up came along about a driver not being installed properly, it wasnt a GPU driver but a security devise driver called AMD PSP 3.0 Device. After installing the driver and restarting the pc the chrome artifacts stopped. I am aware that this is just a CPU security cryptographic thingy and icant explain how they might be related, I am just documenting what i observed. None the less i ve been running fine for the past month, although i am scared off messing with oc and driver updates in case the problem come back.