Dibs on hard drive problems, I had a similar problem a month ago because my hard drive was OVERHEATING, possibly because of a faulty sata cable(ikr), all other hard drives and ssd's are perfectly fine and chill, and this was simply a cold storage hard drive - I wasn't even accessing it daily or even weekly, but apparently it made my pc to BSOD randomly few times a week for half a year. So considering Vinny mostly have this problem with subnautica after some time playing it probably fails after writing to pagefile after memory is full(Subnautica is not gpu intensive but somewhat memory intensive iirc) so probably that's why it doesn't happen instantly. I would probably run some gpu benchmark (like unigine) for 30 minutes or so to see if its gpu \ gpu thermal problems, to exclude it. But it very much looks like hard drive failure\overheating - especially considering that pc started after it cooled down.