During the database shutdown process, this alert is written to the alert log file because the processes of the running jobs cannot be propagated. The warning can be easily ignored. It’s not a problem, it’s normal behavior.
If the “_JOB_QUEUE_INTERVAL” parameter value is increased, this alert will be written less to the alert log file. It takes the value in seconds.
You can change the parameter as follows.
SQL> alter system set "_job_queue_interval"=120 scope=spfile sid='*';
Since “Scope = spfile” is specified, it will be active when the database is restarted.