[Low Key]

I had a problem once of the PS connection to the MB not being tight enough/all the way snapped in. My pc would randomly restart, not turn off, though.

If nothing else helps, get some sage in a tight bundle, light it on fire, and walk around the room holding it near the walls. This is called "smudging" the room, and will help clear out any bad "pc power off" ghosts that may be lingering and toying with your computer.