If you face the issue that scheduled jobs (for example, BOM import jobs) are not running, check the setting of job_queue_processes in your database.
Ensure that job_queue_processes is set to a sufficient value on your CDB, because the value in the CDB cannot be exceeded by the PDB value.
If a simple run-once job doesn't run, you can try restarting the scheduler on the root database as follows:
SQL> exec dbms_scheduler.set_scheduler_attribute('SCHEDULER_DISABLED', 'TRUE');
SQL> alter system set job_queue_processes=0;
SQL> exec dbms_ijob.set_enabled(FALSE);
SQL> alter system flush shared_pool;
SQL> alter system flush shared_pool;
SQL> exec dbms_ijob.set_enabled(TRUE);
SQL> alter system set job_queue_processes=99;
SQL> exec dbms_scheduler.set_scheduler_attribute('SCHEDULER_DISABLED', 'FALSE');