Anything could happen. I haven't looked at your page. You may want to post a support incident so you can share your files in a private forum.
The error is in the data type for the name or the descriptions field as defined in the store cart summary in database.
The data type with add to cart does not matter. All items in the cart are actually stored as strings regardless. The type just determines the validation when adding to the cart and doesn't really effect anything, so that could never be the problem.
The problem only occurs when you are trying to add text to a number column, or when you are trying to add text to a text column, but you have it identified as a number in store cart details in database server behavior.