@jmannik ah, indeed. Do you know which server / interface holds the IP 192.168.30.13? I suspect is still VMHost13, but a different interface.
Until the members have configured their master as 192.168.30.13, you'll have this error. This can be done by a call, but since it's a delicate operation, it's better if there are no operations running on the pool. SSH into the VMHost13, and run
xe host-list name-label=VMHost13 --minimal | xargs -I _ xe pool-designate-new-master host-uuid=_
This should write the new IP to the files of all the pool members and stop blocking this issue from enabling HA