Revy Unlimited UpSell Offers

I really loved this app, but it glitched in a big way on a huge sale day resulting is many lost sales. 2 stars because I liked it when we first installed. But then it started adding things to customer carts without them clicking "add to cart" and then when they intentionally wanted to add an item to their cart, it wouldn't let them. I had many frustrated customers and had to uninstall. I really wanted it to work because I like the layout.