I've been having an issue lately with games where my PC will just randomly die (looks like a driver crash) and won't fix itself, and then reboot, lately it's been happening after vsync completely stops working and I get large spikes in FPS.
I haven't personally been able to find out how to fix it and I cannot run undervolting currently as well.
(Radeon VII w/ r7 2700 system, all parts are a few months old at most)