Wrong Down Payment Document in PO History

Dear SAP Expert,

I have a case related with PO History.

Let's say I have a PO no. 123 and whenever I check the PO History by ME23n in item 10, there are DP request, DP/DP request clearing, and DP clearing document.

The problem are:

1. DP request, which has a different purchasing document assignment (ex. PO 456), appeared in PO history 123.

2. And there is DP request, which has none purchasing document assignment, appeared also in PO history 123.

So it affected to the DP document or DP request clearing, there is DP document which has different PO no, in the PO history 123.

There is no case like this before in our system.

How could it be happened?

Thank you for your solutions before.

Best regards,

Rosida