unified auditing did not purge

Hi all,

Please advise on what is going on?

database 19.24 on solaris 11.4
unified auditing did not purge.

In this case, any unified audit records order by 3/22 should be purged. It said procedure completed successfully and No error. But nothing has been purged.

I have 21 records in 3/20 and they still exists.

SQL> select systimestamp - 4 from dual;
2025-03-22 12:50:29

begin
dbms_audit_mgmt.set_last_archive_timestamp
(audit_trail_type=> dbms_audit_mgmt.audit_trail_unified,
last_archive_time => systimestamp - 4); <<-----
dbms_audit_mgmt.clean_audit_trail ( audit_trail_type=> dbms_audit_mgmt.audit_trail_unified,
use_last_arch_timestamp => true); <<------