Woocommer site filter fix

please read first details I need it done now .. not tomorrow Im managing an e-commerce with several variable products. I have installed Woocommerce Ajax product filter, to filter products on the related product page. There are so many variable products with different sizes, so when i filter product for a certain size it should return all product with that size. The thing is, many variations (then sizes) have stock quantity = 0 and when i filter products for that size, they show up instead of not be visible.