Greetings @Tristan Sounds like the motherboard can't read the drive. It tries to wake from hibernate, can't locate the drive, reboots. With CSM disabled, default behavior if no bootable device is detected, is to enter the BIOS. Seems to match your symptoms. So we have to figure out why the drive isn't detected on wake. I assume your system is in hibernate rather than just sleep when this occurs, correct?What drive do you have?
If you go in to the advance power options in the computer, what is the power plan the computer is set to?
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