Upon opening the RPAC via Management Center the Database and log source configuration looks like on the below picture.
The issue is caused by the lack of privileges for the used role.
If your Reporter appliance is running 220.127.116.11 or later, use the default Admin role Reporter to add Reporter to Management Center. When using the Admin role, you must specify the role as "_admin”
Fro more details on configuration of the connection from Management Center to Reporter visit the below techdoc