After ODA 19.6 upgrade databases display wrong sysdate from connections via listener

Hi, Since the guy affected to my SR has gone awol, I’ll try to ask my question here.

We’ve finished the 18.8 to 19.6 ODA upgrade that include an Oracle Linux 6 to Oracle Linux 7 upgrade.

Users are reporting a 1 hour time drift from their app. Problem confirmed via sqlplus on my workstation.

Seems like the databases started with a wrong timezone :

SQL> select to_char(ORIGINATING_TIMESTAMP,'YYYY/MM/DD HH24:MI:SS TZH:TZM') from V$DIAG_ALERT_EXT WHERE trim(COMPONENT_ID)='rdbms' and MESSAGE_TEXT like ('PMON started with%') order by originating_timestamp desc;

TO_CHAR(ORIGINATING_TIMEST