Audit records are not purged as configured

Hi,

I'm using Oracle 12cR1. I configured Oracle audit (mixed mode), and the purge jobs as below.

A scheduled job 'audit_last_archive_time' is to set the last_archive_ts to 15 days ago everyday.

A scheduled job PURGE_ALL_AUDIT_TRAILS is to purge all kinds of audit records.

SQL> select * from DBA_AUDIT_MGMT_CLEANUP_JOBS;

JOB_NAME                  JOB_STAT AUDIT_TRAIL
------------------------- -------- --------------------
JOB_FREQUENCY                  USE JOB_CON
------------------------------ --- -------
PURGE_ALL_AUDIT_TRAILS    ENABLED  ALL AUDIT TRAILS
FREQ=HOURLY;INTERVAL=2         YES CURRENT

SQL> select audit_trail, last_archive_ts from DBA_AUDIT_MGMT_LAST_ARCH_TS;