PS5 crashes and requires system software reinstall when vertical

Title. I got this unit from a game shop going oob sale as is with no info. The guy thought it might be software related but wasn't sure. When using the console horizontal I have seen 0 issues so far. Games install from network and disc fine. No excessive heat or anything but if it's running vertically after about 30 minutes or so it will power off and I have to reinstall system software via usb. It appears very clean and the warranty seals are still in tact. Any suggestions would be helpful.