HyperV backups when they move between servers in the cluster

I have been testing HyperV backups. I have installed the Netbackup client on the HyperV server, setup a HyperV policy on the backup master, and 'selected' the clients that currently reside on that HyperV server. The backups work fine.

But since this is a HyperV cluster the clients *could* move to another HyperV server in the cluster. The backup then fails with return code = 4203.

How do people deal with this? I dont want to constantly be watching for failed backups and moving clients around between policies.