If you are using another query inside `restrict_manage_posts` make sure you add `&& $query->is_main_query()` to your parse_query if statement, otherwise the parse_query filter will interfere with that second query. `if ( 'POST_TYPE' == $type && is_admin() && $pagenow=='edit.php' && isset($_GET['ADMIN_FILTER_FIELD_VALUE']) && $_GET['ADMIN_FILTER_FIELD_VALUE'] != '' && $query->is_main_query() ) { $query->query_vars['meta_key'] = 'META_KEY'; $query->query_vars['meta_value'] = $_GET['ADMIN_FILTER_FIELD_VALUE']; }`