When in the cart , if a customer adds 2 products (under Buy1Get1 offer), he gets free shipping. For e.g. of a customer added $75 worth 1 products and another product of $65 - he is getting free shipping. Seems the cart is calculating $75 + $65 = $ 140 as sub-total and offers free shipping. And then offers Buy1 Get1 free.
Ideally the calculations should be done on the "Total" value of the cart. How to fix this