Need shipping cost charged per item

-- HikaShop version -- : 3.4.1
-- HikaMarket version -- : 2.1.1
-- Joomla version -- : 3.8.10
-- PHP version -- : 7.0.25
-- Browser(s) name and version -- : na
-- Error-message(debug-mod must be tuned on) -- : none

Doing a peer to peer art sales site. For now, I'm allowing 3 shipping methods: USPS Priority Mail Small Flat Rate Box, USPS Priority Mail Medium Flat Rate Box, USPS Priority Mail Large Flat Rate Box.

I've got the plugin pulling rates from USPS. Problem is that if more than one item is added to the cart, the cart only charges shipping for one item. I need it to charge the full shipping price for each item, since they will all be shipped separately.

I seem to be missing something.

Yes, I'm using shipping per vendor. But the cart is only adding one shipping method. It's not recognizing the send vendor's shipping, and not charging for it.

I also need the shipping amount to apply to each item ordered. So if someone orders 3 products, they are charged 3 shipping fees, no matter how many vendors are in the order.

The site sells one of a kind pieces, so I'm using a product template to restrict the stock of each product to one.

The USPS plugin is working fine.

Thanks!