Magento 2 has the concept of Configurable and Bundled products. These two types of products can be considered "container" products that are not real products but contain one or more Simple products. By default, Shiptheory will ignore these parent container products and download the individual Simple products.
It is possible to change this behaviour so that Shiptheory considers the parent container products as Simple products and download them as normal (providing the parent product has a unique SKU), as well as downloading the individual Simple products. It is important to consider that if you disable this functionality and Shiptheory downloads parent products, those product lines will appear on shipping labels, customs paperwork and may be used in electronic customs data and may result in those items displaying the wrong number, duplicated or empty products.
If you wish to disable/enable this functionality, you can do so by expanding the section the Magento 2 page within your Shiptheory account:
If you have questions regarding this functionality, please reach out to support.