add to cart button broken after woocommerce 4.x upgrade

After upgrading to woocommerce 4.0 the add to cart button should add product to cart and stay on same product page. I have cart page disabled so when clicking on cart u goto checkout immediatly.

used to work fine till woocommerce 4.x.
Now add to cart always take u to checkout page, when disabling this plugin problem is gone.

Hope the maker can fix it, kinda useless now