ORA-30013 undo Tablespace currently in use during PDB open

DB - Oracle 12.2.0.1 2 node RAC with multitenant
OS - Soalris SPARC 11.3

When a 2 node RAC cluster instances were restarted the CDB instance was opened successfully but the PDB was not opening with below errors on the alert log. PDB was on mounted state and not went to 'Restricted' mode.

 2020-05-18T04:28:53.167538+05:30  
 alter pluggable database PRODONL open  
 PRODONL(6):Autotune of undo retention is turned on.  
 2020-05-18T04:28:54.452346+05:30  
 PRODONL(6):attach called for domid 6 (domuid: 0xf8d86493, options: 0x4, pid: 20026)  
 PRODONL(6):queued attach broadcast request 43f144a50  
 PRODONL(6):Endian type of dictionary set to big  
 2020-05-18T04:28:55.523090+05:30  
 PRODONL(6):Undo initialization errored: err:30013 serial:0 start:4085472674 end:4085472823 diff:149 ms (0.1 seconds)  
 Pdb PRODONL hit error 30013 during open read write (1) and will be closed.  
 2020-05-18T04:28:55.524179+05:30  
 Errors in file /u01/app/oracle/product/12.2.0/diag/rdbms/dbaonlin/DBAONLIN1/trace/DBAONLIN1_ora_20026.trc:  
 ORA-30013: undo tablespace 'UNDO2' is currently in use  
 PRODONL(6):JIT: pid 20026 requesting stop  
 PRODONL(6):detach called for domid 6 (domuid: 0xf8d86493, options: 0x10, pid: 20026)  
 PRODONL(6):queued detach broadcast request 43f144a00  
 2020-05-18T04:28:56.600493+05:30  
 ORA-30013 signalled during: alter pluggable database PRODONL open...  

PDBs ware configured use to Local Undo mode (Undo Modes in 12.2 Multitenant Databases) and the strange part was, PDB on node 1 is looking for 'UNDO2', which is the local undo tablespace defined for node 2 of the RAC.

We have decided to operate on the opened RAC node and raised a SR with Oracle, which pointed to unpublished bug, Bug - 24808699 - PDB Created On Local Undo CDB RAC Db Fails To Open As UNDOTBS1 Already In Use.

The solutions was to explicitly set the correct undo Tablesapce name, in our case below.

 SQL> show pdbs;  
 CON_ID CON_NAME OPEN MODE RESTRICTED  
 ---------- ------------------------------ ---------- ----------  
 6 PRODONL MOUNTED  
 SQL> startup;  
 ORA-30013: undo tablespace 'UNDO2' is currently in use  
 SQL> show pdbs;  
 CON_ID CON_NAME OPEN MODE RESTRICTED  
 ---------- ------------------------------ ---------- ----------  
 6 PRODONL MOUNTED  
 SQL> alter system set undo_tablespace=UNDO1 container=current scope=spfile;  
 System altered.  
 SQL> startup;