PC freezes then reboots when using fps unlocker while playing for some time.

[Imperial-Egineer]

Hello I have this problem where I try to use the borderless mode I get a freeze/reboot after playing a while. For exlcusive mode is way more worst I get a BSOD and pc restarts. My gpu (RX 6600) is undervolted and I tested its stability via stress testing it on Furmark. Stressed test about 40 mins pc did not crash. Played other games at max settings like world of warships and world of tanks there is no issue on PC freeze/reboot. GPU usage reaching (89-95%) power 89-95 watts. Temperatures are fine.