Woocommerce Ajax Añadir al carrito no funciona

En WooCommerce el método Ajax para añadir al carrito no funciona cuando el carrito está vacío, si el carrito contiene algo entonces mi función Ajax añade pero si el carrito está vacío no añade. Y no hay error.

Aquí está el enlace. Función PHP para añadir al carrito:

function add_custom_product_meta() {
    global $woocommerce, $wpdb;

    $item_id = isset($_POST['item_id']) ? apply_filters( 'woocommerce_add_to_cart_product_id', absint( $_POST['item_id'] ) ) : FALSE;
    $quantity = empty( $_POST['quantity'] ) ? 1 : wc_stock_amount( $_POST['quantity'] );
    $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $item_id, $quantity );
    $product_status    = get_post_status( $item_id );

    $variation_id = isset($_POST['variation_id']) ? $_POST['variation_id'] : 0;
    $atributes = isset($_POST['atributes']) ? $_POST['atributes'] : 'Small';
    $attribute_pa_macaroons = isset($_POST['attribute_pa_macaroons']) ? $_POST['attribute_pa_macaroons'] : FALSE;

    if($attribute_pa_macaroons && $passed_validation && $woocommerce->cart->add_to_cart( $item_id, $quantity, $variation_id, array( 'attribute_size' => $atributes,  "macaroons" => $attribute_pa_macaroons))){

        //$added = $woocommerce->cart->add_to_cart( $item_id, $quantity, $variation_id, array( 'attribute_size' => $atributes,  "macaroons" => $attribute_pa_macaroons));

        do_action( 'woocommerce_ajax_added_to_cart', $item_id );

        if ( get_option( 'woocommerce_cart_redirect_after_add' ) == 'yes' ) {
            wc_add_to_cart_message( $item_id );
        }

        WC_AJAX::get_refreshed_fragments();

        echo json_encode(array(
            'atributes' => $atributes,
            'macaroons' => $attribute_pa_macaroons,
            'product_added' => TRUE,
            'ajax_complete' => TRUE,
            'posted' => isset($_POST['item_id']) ? $woocommerce->cart : 'item_id is empty'
        ));
        wp_die();
    }

    echo json_encode(array(
        'product_id' => FALSE,
        'product_added' => FALSE,
        'ajax_complete' => TRUE,
        'posted' => $attribute_pa_macaroons
    ));
    wp_die();
}

Llamada Ajax en Javascript:

$.ajax({
                        type : 'post',
                        dataType : 'json',
                        url : woocommerce_params.ajax_url,
                        data : {
                            'action' : 'elephas_addtocart_box',
                            'item_id' : itemID,
                            'quantity' : quantity,
                            'variation_id' : variathionID,
                            'atributes' : atributes,
                            'attribute_pa_macaroons' : itemData
                        }
                    })
                    .done(function(response){
                        if(response.ajax_complete){
                            document.location.reload(true);
                        }
                    })
                    .error(function(error){
                        console.log(error);
                    })
                    .always(function(response){
                        if(response.ajax_complete){
                            document.location.reload(true);
                        }
                    });