Additional optimization to save up crawling budget. Added $link = str_replace('%2C', ',', $link); on line 513 https://mydomain.com/produkt-kategorie/my-category/?filter_filter-color=orange,black If you add another filter it encodes the existing commas: https://mydomain.com/produkt-kategorie/my-category/?filter_filter-color=orange%2Cblack&filter_manufacturer=adidas&filter_cut=men.children So sometimes you have "," as seperator and sometimes you have encoded "%2C". After implementing this pull-request the seperator stays ",": https://mydomain.com/produkt-kategorie/my-category/?filter_filter-farbe=orange,black&filter_manufacturer=adidas&filter_cut=men.children This pull request belongs to the optimization https://github.com/woocommerce/woocommerce/pull/17134 to save up crawling budget,