When shutting down a vSAN cluster, should the "Shutdown Cluster" wizard fail DO NOT click on "Turn Off vSAN".
"Turn Off vSAN" is to DISABLE all vSAN services on the cluster, NOT to power down the cluster.
If you use "Turn Off vSAN" while the cluster is shutting down, upon powering up the cluster vSAN will show as disabled in vCenter and possibly at the host level depending on how far in the disable process it gets before the hosts shut down.