check out page shipping calculation not working for guest users

My Website demo link
interfazia.net/frank/a1

customer login, shipping calculation working perfectly there’s no issues on this plugin. when i come to guest users login, check out page shipping calculation not working. when i change the state of the billing address it will update or reflect the shipping calculation. when click ship to different address button in the upper it will take the ship to different address state and worked, when remove the ship to different address button click it will work for billing address state, but i change the state it’s not working kindly solve this problem, whether it’s theme problem or plugin problem cannot able to get clear solution. kindly do the needful