i have a wordpress with woocommerce plugin but when i trying to set featured some product on woocommerce product page that star used to set featured item show yes but in phpmyadmin there is no change on _featured of the item i use firefox inspect element in the network tap when i click on star buttom i got 302 error on:"wp-admin/admin-ajax.php?action=woocommerce_feature_product&product_id=74&_wpnonce=2bd42dcb1e" i disable all other plugins and there is no change in functions.php of my theme i realy dont know why this happen befor the woocommerce major update(ver 3) every thing is ok but after that i cant featured some item. my woocommerce ver: 3.0.3 my wordpress ver: 4.7.3
From WooCommerce v3.0 featured items are not tracked by meta any more they are now Taxonomy. That's why you don't see the featured meta getting updated.
Featured products are also using the new product_visibility taxonomy instead of meta which improves queries on those.
Read the blog here