All but 1 PDB running on listener

I am running a CDB with 3 PDBS on a system with 2 listeners configured on a 2-node 19.21 RAC installation. The CDB and 2 PDBs are running on both listeners. The 3rd PDB is running on 1 listener but not the second listener.

• The CDB and all 3 PDBs have identical local_listener, remote_listener, and listener_networks parameters. The services for the CDB and all 3 PDBs are running.
• I have already run "alter system register" against the PDBs. This had no affect as it is still showing as a service on listener_1 but not listener_2
• Note that listener_1 and listener_2 use 2 different ports, which are reflected in the local_listener and listen_network parameters