Why do I see more provinces than I have configured?
It is possible that you have configured shipping rates for a country without including all its provinces. However, in the app widget province selector, you may see all the provinces:

If this happens it is because the app is not updated to its latest version. Due to recent changes on the Shopify platform, Shipping Rates Calculator Plus requires a different permission set to work correctly on your store.
To update the app, please go to the app preferences dashboard in your Shopify admin and you will be automatically prompted to update the app.
Once it is updated, we recommend refreshing the cache to ensure the right behaviour out of the box. To do so, please go to the Advances preferences section and click on the Refresh cache button:
