3351101 - MM_PUR_S4_PR_MODIFY_ITEM call

You have an implementation of the BADI MM_PUR_S4_PR_MODIFY_ITEM.

The Purchase requisition is created through a sales order ( integrated with the sales order item type configuration) and the BADI is not called.

SAP S/4HANA Cloud 

MM_PUR_S4_PR_MODIFY_ITEM BADI is called only if the PR is created via MEREQ stack.

Purchase requisition is  created via Sales order is through EBNE stack where this BADI is not applicable and is not called 

This is the standard design. 

In case you need the BADI call for the Purchase requisition created by sales orders you have to edit the PR. 

The edit action from any Procure App will call the BADI. You can use the Mass Changes Apps in case you want to run the BADI for several Purchase requisitions.

KBA , MM-PUR-REQ , Purchase Requisitions , Problem