I've run into something similar- Compare the 1709 and 1803 VMs in vCenter to see where the AppVol vmdk is being mounted. When I ran into this, AppVol was bolting it on to my old provisioning target. Renaming my new target and re-joining the domain cleared it up for me.
Yep - that was it. I figured that the provisioning process was being started on another VM somewhere since it was a clone but couldn't track it down. I was doing a domain drop and rejoin but was still using the old name. I dropped it from the domain, changed the name, and rejoined and now it's working like it should. Thanks MrCheesecake!