WooCommerce Reporting and Custom Order Statuses Documentation
It’s important to note that there has been a bug in WooCommerce since version 2.2.10 that prevents custom order statuses from being shown properly in the reports section. This is something that WooCommerce Amazon Fulfillment can’t control or get around.
We documented it and submitted a ticket here (but so far WooCommerce has not responded):
One workaround for now would be to bulk edit all “Sent to FBA” status orders and change them to “Complete.”
To bulk edit your orders, install this plugin:
Use it for the “product” post type.
Set the custom field called: “ns_fba_is_fulfill”
to the value: “yes”