ORA-16632: instance being added to database profile

 I have a two-node RAC primary database (Oracle 11.1.0.7). I just created a two-node RAC Standby database. I added the Standby to the DG Broker config.

DGMGRL> add database ress as connect identifier is RESS
> maintained as physical;
Database "ress" added

Only one of the RAC instances was added. The other one does not show up and I get the ORA-16632 error:

DGMGRL> show database ress;

Database
  Name:            ress
  Role:            PHYSICAL STANDBY
  Enabled:         YES
  Intended State:  APPLY-ON
  Instance(s):
    ress1

Current status for "ress":
Warning: ORA-16632: instance being added to database profile

The Instance(s) value should show both "ress1" and "ress2". I can show the first instance: