TaxCloud + AwoCoupon - Shipping coupon bug?

-- url of the page with the problem -- : www.weareecs.com/shop
-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.4.7
-- PHP version -- : 5.4.16
-- Error-message(debug-mod must be tuned on) -- : N/A

I'm really not quite sure how to approach this, since the's a Hikashop issue that related to the interoperability of two separate 3rd party plugins.

We're using TaxCloud for WA State sales tax, and we're using AwoCoupon Pro for coupons, including shipping discounts.

One of our primary coupons is a pickup coupon that does a 100% discount on shipping.

Here's the problem: For a taxable items, if its being shipped, Taxcloud works as expected and I see both the shipping and the tax in the cart.

When the 100% shipping discount is applied, the shipping is correctly removed from the cart (or rather, a discount equal to the shipping amount is applied to the total.) HOWEVER, we also lose the Taxcloud added tax line item from the cart entirely.

This is also true on a non-shippable item. If somebody applies the pickup coupon to a virtual good, it completely removes the TaxCloud line item from the cart.

Any suggestions as to how to approach this?

(I'm not on Hikashop 2.6.0 as there were some USPS related bugs last time I used it)

Note: Updated to Hikashop 2.6.0, problem still exists.