shipping fees

Dear support team,
I have an issue with your plugin
when a store adds a shipping fees, the fees are saved correctly. When I add the products from such a store to the cart the fees are calculated correctly too.

However, look at this scenario please:

1) added product from X store which its shipping fee is $2.
2) added product from Y store which its shipping fee is $3.
3) this shipping cost for both of them is $2 for each.

What is happening is that any product on the top from any store, this store’s shipping fee will be calculated for the rest ! It’s very weird!
So if Y store is the first in the list, the X store shipping fees will be changed to $3 !

The page I need help with: [log in to see the link]