Hetzner makes their own servers in a form factor that works for their rack space. There are lots of YouTube videos on that. I don’t know specifically why these are failing, but being an old time engineer and knowing the CPU they are running, I am going to bet it has something to do with cooling. Either the main board is getting too hot (I monitor CPU temp and that seemed fine) or it is related to either vibration from the certainly larger CPU fan it needs, or somehow related to how the CPU impacts the power supply - possibly creating noise that ultimately burns out capacitors or something similar.
DaGeek247