JD Edwards EnterpriseOne- despite Lot becoming effective MRP run B Message, excess supply

JD Edwards EnterpriseOne

9.2 with ESU Patch done

& 9.1 without ESU Patch

Issue- On hand-let's say 0 with safety stock 20, Po already receipted of 20 and in testing hence in supply & demand we see Lot becomes effective on let's say 24/12. Assume no other demand. It balances the supply and demand counting it as incoming supply. However MRP message we get a B, order and expedite message. With it's effective day after the 24/12. why would it prompt for an action message at all? In some cases if there is an additional PO that is created let's say for O1st Feb for demand on O1st Feb of 30, in that