This is a common issue across merchants when importing orders into Shopify.
When orders are not imported correctly into Shopify, an issue shows up in Rich Returns with customers not being able to initiate a return for these orders.
The root cause for this is that the items in these imported orders are not associated with the actual products and variants in your Shopify store.
There are three common ways to check this when you look at such an imported order:
the item in the order does not have an image
the item in the order cannot be clicked on for more details
(technical) the Shopify API will show a "product_exists: false" for the item as well as no product_id and no variant_id
Important to note: this is an issue with the order imported into Shopify, not with us. Any external system will not be able to process these imported orders if they rely on valid product data in these orders.
Therefore returns cannot be processed for these imported orders as we rely on valid order data with product information being available on the order.
How to resolve?
Make sure that the developer or App you work with to import the orders fills the necessary fields of 'productId' and 'variantId' for the items in the orders so that they can be associated with the products in your Shopify store.