We have to ship each item separately as our items are "oversized" and cannot be combined. Before the SP-API switch, we were able to split our Amazon Prime (Buy Shipping) orders in ShipStation. Not multiple packages, but split orders. This would integrate pretty well with Amazon Prime for the most part unless the order was 50+ items. For example, for one order with 10 items, we'd get 10 labels created and 10 tracking numbers in the Amazon interface/ShipStation.
Now with the SP-API, it's glitching horribly. We'd get error messages almost every batch. For example, out of two items (same order), only ONE item successfully ships in ShipStation. The other one would result in an error and stay in "Awaiting Shipment". But in the Amazon interface, it would show that the one label was created for BOTH of the items and they are both shipped under the same label.
Or sometimes one of them has shipped and the other hasn't on both Amazon and ShipStation. But for some reason, we are unable to create a label for the unshipped item.
Another example: Sometimes Amazon does show that both items have shipped, separately, with their own tracking numbers... But it has not been carried over to ShipStation (one item remains "Awaiting Shipment") while the specific label for the item that is "awaiting shipment" cannot be downloaded or voided off Amazon.
This is not something that happened at all with the old API.
Also note that with the SP-API change, order reports are not as accurate and our order stats/reports we're pulling from ShipStation and Amazon are not quite matching up (especially order time).
Is anyone else dealing with this issue?