I had just the same problem, VMs were all still running fine!
I searched the whole array and found that all VMs were stored in a randome Subfolder of my Documents Share.
The day before they were all sitting in the VM Share and Main Folder... very strange
Hey, i'am monitoring the docker with top and installing, configurating inside the docker via ssh.
It's more convenient for me using ssh, over the consol funtion inside unraid.