Believe it or not the system is working as QAD designed it. Now that does not mean their logic is correct but it is working as designed.
The part that is missing from your question is what the actual DELIVERY schedule was.
Supplier schedules do not use the receipt quantity to calculate the price of the material.
If a price list is defined for the item (type "p") the supplier schedule will use that price list. The process uses the quantity on the schedule (188.8.131.52) to determine the cost of the purchase. The purchase receipt is processed against an effective date.
The program uses the effective date to decide which release (184.108.40.206) should be used. The release quantity is considered as the quantity to apply as the minimum quantity of the order.
To help explain this further look at the example below.
Let us assume we have a type “P” Price list with three break points:
Min Qty Price
And we have a released (220.127.116.11) schedule as follows:
Date Quantity F/P
07/13/17 20.0 P
07/20/17 10.0 P
07/27/17 30.0 P
The price of the material depends on both the effective date of the receipt and the schedule quantity.
Materials received during the first week (07/13/17) will cost $20.00 since the expected quantity for the week is twenty units. Once twenty units have been received, the pricing of the material will be based upon the expected receipts for the next bucked quantity. Ten units are expected for the second week (07/20/17), therefore all receipts will cost $30.00. The $30.00 cost will remain in effect until the cumulative received exceeds thirty units. Once this threshold is passed, the costs for the materials will be based upon the next bucketed demand (30 units), the cost for the units will be $10.00.
Programmatically, the process is handled by comparing the schedule cumulative quantity (schd_cum_qty) and the cumulative quantity received (cumulative quantity plus receipt being processed). The price table quantity is the first instance whereby the schedule quantity exceeds the receipt quantity.