shipping rate table + free shipping coupon = not working

i installed shipping pro basic, with table for Canada/USA/REST OF WORLD. tested and working all ok. however, I am finding that coupon codes for free shipping i have set up does not seem to work on the shipping pro shipping rates shown for orders if under my free shipping rate of $100 setup through the native woocommerce shipping (why the coupon code was generated). The coupon itself is working and can be applied. ( code: wlnks89lwn). please have a look flashvape.com/shop , put any of the cheaper (under $100) products in cart, then apply coupon, you will see the shipping rate still there and added to total. thanks~