Many customers always have trouble adding to cart, where the vast majority use phones to make purchases. Apparently phone browsers have a navigation bar that does not allow to see the add to cart button. I attach a video link, this is a very problematic problem, the only solution is to give the link directly to the customer which is quite redundant, this site is embedded to Google Sites a tool used to gather all the content of my business and give the link directly from the catalog would discard the function that has Google Sites in my business.
Link video: Watch Problem embed, shopping cart. | Streamable