When you have a MS SQL cluster there are at least two physical and one virtual (common) node. If you try to refresh the list of SQL user accounts by connecting to the physical nodes, you will be unable to connect and the procedure will fail. THis is expected behavior as the query must be routed through common virtual node.
Q: If I route through the common virtual node, how will I see the SQL accounts on a specific server?
A: Because the information is shared 100% within the cluster, both nodes effectively have the same permissions, users, tables, etc. Connecting to the common provides access to all accounts within the cluster.