How to protect a clustered resource with a secondary DPM server after Primary DPM server is decomissioned

Hi

We currently backup an 8 node Hyper-V cluster on a DPM 2019 server which is protected by a secondary DPM server. The primary server is being removed and the secondary server has been relocated.

A VM on the cluster has been moved onto a new stand alone Hyper-V server and the agents installed on the new host, however when the VM is added to a new protection group (having been removed from the primary) the secondary DPM cannot protect it as it believes the resource is still protected on the Hyper-V cluster.

When adding into the protection group initially a warning message appears stating "One or more of the selected data sources are already configured for protection on the primary DPM server. When you switch back protection, the replicas of these data sources will be protected from the primary DPM server. (ID: 31162)"

When it is added the protection group shows it being under the primary DPM server instead of the new Hyper-V host. It's protection status is "Unable to configure protection".

Does anyone know how to successfully move a VM on a Hyper-V cluster from a primary to secondary DPM server on a permanent basis, with the primary being subsequently decommissioned as well, or indeed if it is possible? I have seen some articles (Charbel Nemnom and Buchatech) but these have not worked.

Thanks in advance, and all suggestions welcome.