Cart issues 1.7.4.2

[diana]

Hi,

I have 1.7.4.2 version prestashop and have issues with my cart (ajax mode enabled).

 http://shop.smartshape.pl/prestashop_1.7.4.2/  

Sometimes I can't add product to the cart, when I press the 'add to cart' button the cart popups and its empty.

Sometimes when I click 'add to cart' the cart poupup isn't happening and the cart icon is dissaperaing from teh header and I have to back to the main page and click the cart icon there. Then products is in the cart already.

Customer will be able to buy something but it will be complicated.

Please help me asap if you know what is wrong. I wanted to start my shop yesterday...

I saw a lot of solutions but I m just a beginner and I am able to manage UI of presta, not the code. Is it possible to solve the problem in my level?