We are currently having issues with XPO not being listed as the carrier in the drop down menu when we mark an order as shipped. When we update to carrier to "other" and have it sent to the Marketplace (Amazon), it is having our shipments show invalid tracking on Amazon. Amazon has XPO listed as carrier in their selection when updating tracking for an order. We are required not to use "other" when the carrier is listed in the drop down menu. Please add XPO Logistics, Inc., in shipstation. This would help with this issue greatly!