If you have made changes to your location settings in Shopify, you may need to update them in GoSweetSpot or else GoSweetSpot may not be able to fulfill your Shopify orders.
You can do this by navigating to your Shopify integration under Administration -> Integration and inserting clicking 'Edit' on your Shopify integration.
Select your fulfillment location here and then press save:
This fulfillment location will then be used in the future for this Shopify integration.