I reached out to Calcurates app and here is response:
Hello Meredith,
Thanks for your query.
Unfortunately, Calcurates app is not able to solve this and we do not know any other app that is able to do so. Duplicating shipping rates can only be solved with shipping from a single Shopify location, but we realize that this affects your accurate control of inventory. This is “by design” Shopify behaviour that our app cannot bypass.
SO THIS IS A SHOPIFY NOT HELPING ISSUE…I plan to reach out to Shopify everyday until they find a solution.