I was able to find the issue I was having. As it turns out, the red asterisk was on the wrong side of the state selection drop down. Not a huge issue by itself except that Presta was allowing customers to register without actually selecting the state (verified that this is possible and subsequently proceeded through with the transaction, receiving the same error message I had been getting.) Not sure if this is the correct way to fix the issue or not, but in the /controllers/admin/AdminAddressesController.php at line 289 I changed 'required' to true and now if the customer skips over the state selection it returns an error message that a state is required for this country. Hope this helps!