If I add all pve cluster nodes to pdm as remotes, the amount of VM's is multiplied by the number of pve nodes, is this the normal bahaviour? I would expect, each VM only will be counted once.
You need to add only a cluster, and then all the nodes of the cluster appear. If you add each node of the cluster to PDM you may have duplicated (or x 3or x5 depending on the number of nodes) VM in PDM