It's not the psu. If you pull enough to trip protections, you'd need to reset the psu by pulling the plug or hitting the switch. A psu is always On if its plugged in and the switch is 'l' whether the OS is active or not. So it won't reset until 'off'.
A CTD or Windows reset is almost always a driver conflict with something, and that can be anything from bios to the cpu.
There have been reports of AIB 3090's crashing in some titles due to 'dirty power' at extreme frequencies, dropping below 2000MHz seems to solve that.