Hello there!
A friend had an issue where the PC was restarting at random points, first assumption was a bad PSU, he tested a different PSU, no luck unfortunately.
Then we ran memtest86, and it showed a lot of errors, tried with the ram in another build, no errors. Tried good confirmed ram in the problematic PC and it showed errors, then we assumed bad DIMM slots so RMA'd the board.
New board arrived (MSI X570-A PRO) and unfortunately the shutting down issue is still present and errors still show, it actually once restarted during the memtest86 test.
CPU: 3600
GPU: 2080 Ti