Using an alternate 'order fulfillment' app such as ShipStation, if not set up correctly for use with Shopify Marketplace Connect, can easily cause duplicate orders on ShipStation and create confusion.
There are 2 ways to avoid this. Marketplace Connect recommends Option 1 as the most suitable approach to use.
Disconnect Walmart from ShipStation (or the order fulfillment app being used) and send your Shopify orders to ShipStation. This will ensure stock levels are updated on Shopify as soon as we send orders, and the sync is maintained. ShipStation will see all orders and Marketplace Connect will send all the necessary Shipping and Tracking information from ShipStation back to Walmart.
Disable sending orders on a per-marketplace basis from the order screen. If you are selling on multiple marketplaces, ensure the correct marketplace is selected first from the drop-down menu.
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