Opening of database failing with ORA-44304

Hi Team ,

Hope all is good , recently we faced issue with couple of our database with the error mentioned ORA-44304.
Changes :- We upgraded from 19.17 to 19.24

Multitenant , 2 Node RAC database. on OCI Exadata Service
Unable to open the database after the Flashback is completed and getting below errors

SQL> FLASHBACK PLUGGABLE DATABASE <DBNAME>  TO RESTORE POINT PRE_RELEASE;
Flashback complete.
SQL> ALTER PLUGGABLE DATABASE <DBNAME> OPEN READ ONLY INSTANCES=ALL;

ALTER PLUGGABLE DATABASE <DBNAME> OPEN READ ONLY INSTANCES=ALL

*

ERROR at line 1:

ORA-65107: Error encountered when processing the current task on instance:1

ORA-44304: service dbname_fan does not exist

ORA-06512: at "SYS.DBMS_SYS_ERROR", line 86