PO Quantity is not updating
I would like to ask, is the PO quantity cannot be updated anymore if the delivery for this PO is already included in the transportation plan? Because our issue is that, the user tries to update the quantity of the PO but upon checking via ME23N, the new quantity is not reflecting. What I noticed is that
1. the delivery of this PO is already included in the transportation plant ( I am receiving this pop up warning message "Delivery XXXXXXXX already included in transportation plan. (Changes are not sent to OTM anymore)." Does it mean that the new quanity not reflecting is the expected result?
2. the function module ME_UPDATE_DOCUMENT is not called upon update debugging it will just processed sucessfully but the new quantity updates are not reflecting.
I am an ABAPer and I am not quite sure about the process as a whole and my functional guy is tagging this one as an issue.
Hope you can help me with this.