Can't access CU of active hosting member through APM webtop

We use an APM webtop to grant access to all our BIG-IP Configuration Utilities. The only BIG-IP CU to which access fails is the active member of the pair hosting the APM webtop. Error message: "You do not have permission to access this page. Access was denied by an access control list." Is there a way to configure access to the active hosting member?