I configured default option of attributes of a product class but during a testing, I click "add to bag" of this product, the default option is not selected.
Re: attribute default option not selected after "add to bag"
Please search for your answers... I'm noticing a lot of your questions are answered all over the place. For example, I know I've clarified this exact same question this past week. You can also review the attributes documentation and make any recommendations if it's incorrect.