Encrypted vhdx moved to new host, boots without pin or recovery key

I just wanted to post an update on this.  I created a new VM but made sure to enable VTPM prior to installing the OS.  Once the VM was up and running, I shut it down and copied the .vhdx to another off-network Hyper-V Host, created a new VM based on the .vhdx I copied over and attempted to boot.  It prompted for a recovery key (as it should).  So, my question is does VTPM only work if you enable it during a fresh VM install or is there a "bug" in Hyper-V where if you enable VTPM on an existing VM, it doesn't work as designed?