Up-sell Ajax causing problem

I have tested and deactivated all plug ins. I filtered down to this plug-in. Every time I add a cart on the single product page, it does not update the cart. I have to refresh or move to a different page for it to update. It’s fixed when I switched off Upsell > Ajax Add To Cart (Use Ajax add to Cart on a single product page.)

It has nothing to do with the Theme (I’ve checked that).

I want to use Ajax so that the page does not refresh itself. How can you help?