Audit on PSOPRDEFN

Hello,

We turned on the Database level auditing on PSOPRDEFN. Used peoplesoft delivered functionality to create the trigger. It does captures the changes ,delete and adds. Two issues we found is audit oprid is tracked is a very random and LASTPSWDCHANGE  getting updated erroneously while there was no password change done. It captured the audit oprid as XXXX when XXXX has no security to the user profile page. From app server logs found that XXXX was logged in at the time of the changes. I believe the function GET_PS_OPRID is not working as expected.   Did any one has similar issues?.