Shipping price for additional item is not calculating correctly

Can you please assist with our pricing.  We want each additional item to have an additional shipping cost but right now the additional item category only applies to that product and not per order. Please advise.

(and fix your chat box! I've tried this a few times and no one replies.)

I have checked your JotForm and see that the Additional item cost is mentioned as $1 in the payment wizard. 

As I tried to select multiple items, I see that the shipping charges are being calculated correctly. The first item @ $3 and the additional 2 items @ $1, total $5 is being calculated correctly for the test.

Please get back to us if you need any further assistance. We will be happy to help. 

(and fix your chat box! I've tried this a few times and no one replies.)

We are sorry about that. Probably all our chat support team might be busy assisting other customers. You may try again to get in touch with our chat support team. Please note that our chat support is available Mon - Fri (9 AM - 6 PM).

Thanks!