Recently trying to run a “Change VM Recovery VRA” command on a host , to migrate a VM to a new Host ,  selecting a specific VM and the new Recovery VRA , and it would not let me Select the Save ( no error either ) 

Opening up the VPG and Clicking Edit VPG , showed the VM had no “Recvory Volume Location” selected , even though the VM had been meeting its RPO.

I had to add this storage location and it start a Full Initial which then allowed me to migrate the VM