Question Any help on why my counter randomly turns off?

[ThePersonInRed]

Whenever gaming on hardware intense games, my computer turns off and won't turn back on again simply by pressing the power button. If I want to get back on the PC, I have to turn the power supply switch off for a few seconds and then turn it back on to get the computer turned on again. I've recently took it back to where I got it under warranty, but the engineers there say it is not faulty. Any help on what could make it turn off?

 

[rgd1101]

full system spec? include make and model of the psu

 

[ThePersonInRed]

Ryzen9 3900x
250gb ssd Samsung pro
2tb Seagate Barracuda
Aerocool project 7 p850w psu
MSI x470 gaming pro motherboard
Evga gtx 1080ti
2x8gb 3000mhz Corsair vengeance ram