Cannot revert to or delete snapshots

Host: ESXi 5.5

VM: Windows Server 2016

I am trying to clean up snapshots (way too many) for a VM.  I cannot seem to revert to or delete any snapshots. I tried with both VCenter Server (6.5 Appliance) and the Windows Client.

Both act as if the Snapshot is being reverted or deleted successfully (ie, Completed).  However, the Snapshot is still there and and the current snapshot has not changed.

I don't want to select Delete All, because I would like to keep some of the Snapshots.

Any ideas?  Thanks.