Resolution:
When you install a Manager that includes a secondary Director, you must also configure the Manager containing the primary Director. This will register the secondary Director's address with the primary Director, as well as reconfigure the Engine and Driver configurations.

To reconfigure the Manager containing the primary Director, go to the Admin menu, select Manager Reconfigure, and enter the secondary Director's address and port in the corresponding page. This will configure the primary Director to recognize the secondary Director, as well as reconfiguring Engine and Driver configurations accordingly.