[Plugin: eShop] Shipping calculation error

I had a person recently order from Arkansas.

In my store this is a zone 3, and when I checked the order in the system eShop says it processed it as a zone 3. However, the actual amount charged was for zone 5, which is my default shipping zone.

I tested two other orders from different cities in Arkansas and it’s doing the same thing, charging for zone 5 even though it’s in the system as zone 3. Any ideas why?