Enfold + WooCommerce: quantity button on category pages isn't working

this bug is in a live shop with high traffic so it’s very urgent
Please Please help me ASAP

the problem:
if you go to http://www.myshop.com/shop/ (real URL is in the private Content) and press on any of the products ‘+’ quantity button 3 times (e.g you want 3 items of that product) and than you press the ‘add to cart’ button – every thing works as it should and the cart get filled with X3 of the product you chose
BUT
if you go to http://www.myshop.com/product-category/name-of-the-category/ (real URL is in the private Content) and press on any of the products ‘+’ quantity button 3 times (or any other number other than 1) and than you press the ‘add to cart’ button – always only X1 of the product you chose is added to the cart!

..this is a huge bug,
i’m not sure why there is this difference between the category page and the default shop page
please please help me fix it