Random Restarts During Some Games?

I have tested just about everything and cannot for the life of me figure out what is wrong. The game Hell Let Loose is causing my computer to restart with no errors. Here are a list of things I have tested and monitor:

-CPU (Ryzen 7 5800X) temp: ~50-65 Celsius

-GPU (GTX 1080): ~60 Celsius (I know it’s old, but it's working fine for other games, including more demanding games).

-MOBO: B550 PG Velocita

-RAM: Vengeance RGB Pro DDR4 3200MHz 2x16GB (recently installed)

-PSU: 850W RM850X Corsair (just installed, but after restarts started happening, upgraded from 750W)

-Stress test ran on both CPU, GPU, and both together with no issues.

-NVIDIA drivers are up to date.

-Memory check ran, no issues.

-Other tests: Other games work fine. Played enshrouded for 30 min, no issues. I will continue to test other games as well.

-Event viewer shows: Critical: Kernel-Power "The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly." - So not very helpful.

I have lowered the settings and still randomly restarts. Another thing is sometimes I get a restart during startup, or just on the main menu changing settings.

Does anybody have anything else I can test? It is weird to me that sometimes I can play this game for hours, and no issues. Then one day I get on and can barely get to the main menu.

Thank you in advance for any kind of help.