LTTP but just went through this with my 5800X3D and it was a bad CPU…This is the board I used to build my 5950X system with and it was never stable. To the point that the system was completely unusable due to random power-offs that ended up killing my installation of Windows...
I wasn't able to troubleshoot it properly due to lack of available time to waste, so I just drained the coolant and disassembled it.
When I got time about 10 days ago, I installed an air-cooled 5800X and air cooled video card and used different RAM and reloaded Win 10. It's been rock-solid since so the processor, video card, or RAM seems to be the culprit.
https://hardforum.com/threads/b450-aorus-pro-wifi-resetting-rebooting-constantly.2019782/
Bought the Dark Hero as part of troubleshooting and now don’t wanna swap back to my cheap B450.