We have new settings and fields active for you to aid in assigning your items to the correct Shipping Template that you've created on Amazon. You'll find a new field in the Amazon Attributes section of your listing page titled Shipping Template and you'll find matching settings for it in the Amazon Attributes section of the Single List Page Settings. The list you create in your settings will create the drop down menu you see on your listing page.
If you wish to upload this information you can send it using a header of 'amz_shipping_template' (all lower case). Supply the name of the template for the items in your file and that will be the template that we use. Note: if the name of the template that you are uploading does not already exist in your Single List Page Settings the item will display 'default' for the shipping template on the listing page. It would be best to enter the names of your shipping templates to the settings page before sending it via a file. However, if you do not first enter it to your settings, you can use the 'Populate list from Inventory' check to pull those into your list.
Happy Selling! Let us know what questions, or concerns you have.