PO change: Duplicate lines for one request created in CHNG_RQST_DTL

Hello,

We are trying to understand why we have duplicate lines for the some PO request change, inserted in the table CHNG_RQST_DTL, almost at the same time. The process PO_POCHNG is aborting each time after this issue.

We do run this query to find the PO with duplicate change request, we  deny the duplicate line request and rerun the process Po change again:

SELECT PO_ID, LINE_NBR, SCHED_NBR, COUNT(*) FROM PS_CHNG_RQST_DTL

GROUP BY PO_ID,  LINE_NBR, SCHED_NBR

HAVING COUNT(*) > 1

Please, any help is welcome.

Thank you,

Salah.

P.S: the environment is PeopleSoft 9.1, bundle 26, PeopleTools 8.52.13