Oracle 19c with SAP System - ORA-12154: TNS:could not resolve the connect identifier specified For Physical Standby

Question

Oracle 19c + SAP system. On primary side I have a problem when transporting logs to Data Guard side.

Outputs from primary side:

SQL> select status, error from v$archive_dest where dest_id=2;                                                                                                                                      
                                                                                                                                                                                                    
STATUS    ERROR                                                                                                                                                                                     
--------- -----------------------------------------------------------------                                                                                                                         
ERROR     ORA-12154: TNS:could not resolve the connect identifier specified


SQL> show parameter log_archive_dest_2

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_2                   string      SERVICE=DRSIDE NOAFFIRM ASYNC V
                                                 ALID_FOR=(ONLINE_LOGFILES,PRIM
                                                 ARY_ROLE) DB_UNIQUE_NAME=DRSIDE

SQL> show parameter log_archive_dest_state_2                                                                                                                                                        
                                                                                                                                                                                                    
NAME                                 TYPE        VALUE                                                                                                                                              
------------------------------------ ----------- ------------------------------                                                                                                                     
log_archive_dest_state_2             string      ENABLE

Alert log:

TT00 (PID: a number): Error 12154 received logging on to the standby
2021-02-20T15:48:51.144500+03:00
TT00 (PID: a number): Error 12154 received logging on to the standby
2021-02-20T15:53:51.946941+03:00
TT00 (PID: a number): Error 12154 received logging on to the standby
2021-02-20T15:58:52.744327+03:00
TT00 (PID: a number): Error 12154 received logging on to the standby
2021-02-20T16:03:53.549161+03:00
TT00 (PID: a number): Error 12154 received logging on to the standby

I did not make any changes to the tnsnames.ora or listener.ora files.

Edit: I tried to set log_archive_dest_2, I tried to send tnsping (successfully works from primary to disaster and disaster to primary), I tried copying passwordfile from primary to disaster. None of them worked.

Best regards,