Default pdb service not getting registered after migration

Hello experts,

I have migrated a non-cdb database and plugged in successfully in a cdb database.I can see pdb database is open read write and corresponding services.Please see following

SQL> select name,network_name,pdb from cdb_services;

NAME                        NETWORK_NAME     PDB

-------------------------------------------------- -------------------- --------------------

cisxg.world                    cisxg.world     CISX

CISX                        CISX         CISX

SQL> select name,open_mode from v$pdbs;

NAME                        OPEN_MODE

-------------------------------------------------- ------------------------------

CISX                        READ WRITE

lsnrctl status listener_dbac

LSNRCTL for Solaris: Version 19.0.0.0.0 - Production on 03-MAR-2022 20:32:17

Copyright (c) 1991, 2021, Oracle. All rights reserved.

Connecting to (ADDRESS=(PROTOCOL=IPC)(KEY=dbac.world))

STATUS of the LISTENER