Optane P4801X disappearing

Gentlemen, I got this weird problem in my Linux server with the boot drive Optane P4801X vanishing.

My setup is a Ryzen 3900X, Asus Prime x570 Pro, 64 GB of Kingston 2666 ECC Ram, a ZFS pool with 4 drives, 2 more SATA drives for backup in another ZFS pool, 1 nvme drive for Windows gaming VM and 1 nvme drive for linux boot (Optane P4801X). The gaming VM has an MSI 6800 XT passed through. Everything works fine until I am into my 2nd hour or so of gaming. Then the boot drive vanishes. Funnily, the VM and my docker images keep running. Host is Ubuntu 21.04 server.

My only hint might be heat. Looking at Grafana, my CPU hits around 65ish C, same for GPU, SSD is around 57ish C. Optane seems to be tolerant until 70C according to Intel docs.

Do Optanes or SSDs shut down during heat? I see no errors whatsoever in syslog. Is there a way to move syslog into a different drive to see if maybe I can get more info out of it when Optane goes bye bye? Am I not supposed to use these Optanes as normal drives?

Any idea is appreciated, thanks.