We have a project running Commerce 13.7.0 where we break orders in to multiple order forms / shipments, and are having trouble with shipping discount only applying to the most expensive shipping cost, and not the others. IE
Shipment 1 has a shipping cost of 39.76
Shipment 2 (in the same order form) has a shipping costs of 28.00
When we apply a coupon code that should apply a 10% discount, we get total saved of $3.98 and a total shipping cost of $63.78.
I believe I have traced it back to ShippingRewardApplicator.Apply method where it calculatus the remaining shipping costs using the sum of shipments in affectedShipments, and not on a shipment, by shipment level. Is this a bug, or is there an reason for doing this? We can reimplement this the way we need, but wanted to check first.