Good morning, a few days ago I installed the pluggin in 

YITH WooCommerce WooCommerce Deposits / Advances Premium
of YITH that has its page: https://yithemes.com/ even you recommend that you use the plugg inn YITH WooCommerce Wishlist

YITH WooCommerce Deposits / Down Payments Premium is intended to allow the buyer to pay a percentage of the sale or reservation. 
When I installed the plugg in I did not see any error but when I see the product in the check out I do not activate the balance. 

I contacted Yith the creators of the plugg in and they told me this:
"The problem seems to be because the add to cart is done in ajax, maybe it's your theme that does it.
 
Do you know if there is an option to disable that function? Alternatively you could ask the theme developers."

I have already disabled the AJAX function in the back office but it still doesn't work, can you help me to disable the AJAX? 
It affects in some way to the site

Thank you very much for your help

thanks it works