Payment Terms in MIRO

Hello, we have a puzzling situation. The Accounts Payable department is using the MIRO screen to process payments by Vendor. When the PO detail comes up and the PO is checked - the payment terms show Z+30. However, in the section in the middle of the screen, the payments terms are Z+60. This is puzzling since the VEndor Master, Contract, and Scheduling Agreement all show Payment Terms of Z+30. Why would MIRO differ from these documents? What would be the cause?

Any input on the pecking order or the processing logic would be appreciated.

Thanks in Advance!