Postage taken in account after coupon applied

-- url of the page with the problem -- : scarvesaustralia.com.au
-- HikaShop version -- : 2.6.2
-- Joomla version -- : 3.5.1
-- PHP version -- : 5.6

Hello

We have the following scenario. Postage is free for an order over $99 everything under is a simple $10.

Now we have an automatic coupon that gives the client 25% discount if the customer buys 2 items of the same category.

Unfortunately (see screenshot) the postage looks at the subtotal amount which means often no postage is calculated.

How can we achieve to solve this problem?

Wonderful, now it works beautifully.

Thank you Nicolas