ATP over confirmation for order type Consignment Issue

[former_member116200]

Regarding the Consignment Issue order process, when 2 different sessions are placing the order at the same time, and they are asking for the same material for the same customer, they will both get the order quantity confirmed even though there is no enough available stock.

Replicate Steps:

Background:

Customer FR00009 has 20 pieces of Material 01-000000051037 in their consignment stock.

Now user A is placing the consignment issue for this customer and material for 20 pieces, but not saving it, ATP confirmed the delivery schedule line to the requested delivery date:

Now user B starts to placing another consignment issue for the same customer and material for another 17 pieces. SAP unexpectedly confirmed these 17 pieces to the requested delivery date. This is incorrect, because user A already used up all the 20 pieces:

Now both of the users save the orders with success. Let's recheck the ATP situation, the cumu. availability is a negative number that means already over confirmed:

Do any SD expert has any idea or comment about this issue? I've tried the same steps for the standard order, it does work correct, not like the consignment order.

Our Product version is SAP S/4HANA 1610. ATP checking rule for Consignment Issue is AW that is standard, we didn't change any setting for this rule.