Syspolicy_purge_history connection issue
You will need to put the port number in there.  When using the default instance the SQL Browser is not contacted in order to get the port number to use to connect.  Because of this you have to specify the port number when connecting otherwise the OLE/ODBC driver doesn't know what TCP port number to connect to.

Please clarify how you took a standalone server and made it a cluster.  That isn't supported unless you uninstalled SQL and reinstalled it.