So, try it different, what you will see in HWinfo about voltage in load? https://www.fosshub.com/HWiNFO.html/hw64_545_3090.zip
Its bad for me, because I have not here yet the test setup with Ryzen (tomorow with Crosshair).
Iny my theory it could be:
-overheating the CPU or VRM because the vcore is fluctuating to high at auto settings
-Windows 10 issue (Win7 seems more ready for Ryzens as few guys at another forum wrote)
PS:HPET is enabled via cmd in WIndows?