The first thing I'd suggest is updating your motherboard UEFI/BIOS to the latest version. It's surprising what that can fix and it allows us to assume the motherboard is in as stable a state as the manufacturer has been able to achieve. That's assuming the computer is stable while in the UEFI/BIOS setup menus.
After updating I'd then go back into the UEFI/BIOS setup menus, load default (or optimized) settings, and then Save & Exit - that should get rid of any bad settings that might survive the update.
