auditing stopped after windows bundle patch on 12.1.0.2

I have a server running basic 12.1.0.2, audit works fine on all databases, aud$ is populated with correct audit trail records.

I got a new server recently, I installed basic 12.1.0.2 then applied August Windows bundle patch 160831, then created a new database, I ran datapatch against it as the patch readme required. Then I realized the aud$ is empty, init parameters are correct:

SQL> show parameter audit

NAME                                 TYPE        VALUE

------------------------------------ ----------- ---------------------------

audit_file_dest                      string      \APP\ADMIN\MYTST2\ADUMP

audit_sys_operations                 boolean     TRUE

audit_trail                          string      DB

unified_audit_sga_queue_size         integer     1048576

Then I checked 2 other servers, one has April bundle patch, one has October bundle patch, auditing is not working on both of them. aud$ are empty on both databases.