I had a similar experience the only difference between my setup and Siang's is I'm using a Dell R610 with a PERC H200 HBA and no IT mode as it recognized the drives on first boot. The card is configured as a passthrough to the VM and I'm running Proxmox 6.3-3 as my hypervisor. Regardless of the differences I had the eact same problem. Once I removed the H200 passthrough from the VM. I was able to see the box again. I couldn't roll it back so i had to tear down the VM and start over. As Siang said DO NOT UPGRADE to UPDATE 3 for now!
