Multiple Recoverpoint for VM clusters attaching to single Plugin

Is there a password dependency when we have multiple RP4VM clusters attaching to a single plugin-server.

We have two clusters connected across sites at production and DR sites, working with one RP4VM plugin server.

Now we want add a second RP4VM instance, to serve a second VMware cluster, but attached to the same vCenter server. 

The first instance detaches from the plugin server, the moment the second  is attached, and its certificate validated. Is this because the credentials are different ? What's the workaround here ? I do not believe that we can have two RP4VM plugin servers attached the same vCenter.