There seems to be some problem with product filters in woocommerce. You have put in the option to choose how many products are shown in one page. And there is also same filter (if you turn on filters). The option in back end is working. But if I want to change that filter in shop page, then it does not work.
And secondly if I want to sort products by name, then it does not work also – some products are put in alphabetical order, others are not.