For me to get VVols to work, it wasn't the "short name" that I needed to use, but rather the IP address, i.e.:
https://10.201.30.184:8443/vasa/version.xml
VVols and policies were working great for several weeks, now for some reason my storage-policy-based-management (SPBM) isn't working in vCenter but I think it's a vCenter thing and not a Unity thing. Until I get that figured out, my polices are currently broken, but VVol VMs continue to remain running. Not sure if it's certificate related again, or something else, but I must say VVol troubleshooting is NOT fun.
I do see all Protocol Endpoint LUNs (LUN 1023, etc.) on my ESXi hosts, and the CLI output shows the VASA provider communication working, and that was fixed after I started using IP address for the VASA provider URL.
Hope this helps.
Bill