Some marketplaces provide custom order statuses that must be mapped to ShipStation's default order statuses. If you notice that orders are missing from ShipStation, be sure that the missing order's status is mapped appropriately in ShipStation.
Head to your Account Settings (the wrench icon in the upper right).
Next, select Selling Channels and then Store Setup from the sidebar on the left.
Find your store, and choose the Edit link under Actions.
Remember, this is only available for shopping carts that support custom order status mappings. Under the Store Information sub-tab, find the Your Order Statuses section, and enter the custom status(es) from your marketplace that correlate to each ShipStation status.
Important Notes About ShipStation Order Statuses:
Awaiting Payment - Orders that are in this status cannot be shipped. They must be marked as paid, which moves them to Awaiting Shipment. Keep in mind that some marketplaces do not import unpaid orders into Awaiting Payment.
Awaiting Shipment - This status displays all open orders that need to be shipped. Enter any order status that you use that states an order is ready for shipping.
Shipped - Orders in this status were either shipped using ShipStation (that is, they had a label created or were marked as shipped by a user in ShipStation), were imported as shipped from the marketplace (because they were shipped outside of ShipStation and the status updated before the order imported), or updated by a marketplace refresh (again, shipped outside of ShipStation and marked as shipped on your marketplace). To confirm how this order was moved to the Shipped status, select the order, then click the Activity Log panel.
Cancelled - Orders in this status have either been updated as cancelled by the marketplace or cancelled within ShipStation. Please note that ShipStation updates orders as cancelled from your marketplace; however, if you cancel an order in ShipStation, it will not update back to your marketplace.
On Hold - Displays orders that have been manually placed "On Hold", because the item is on back-order, is partially fulfilled, etc. Orders can be taken out of on hold via the "Hold Until" date expiration, manual order status adjustment in ShipStation, or marketplace status update.
Shopping Carts that Support Custom Order Status Mappings:
Magento Community, Professional, Enterprise