I am using the following code to allow adding multiple items via url (...com/checkout/?add-to-cart=632:11,422:7) to the woocommerce cart. Somehow it does not empty the logged in OR logged out users cart before adding the new items using WC()->cart->empty_cart();. Any idea why?

    // Function to allow adding mulitple items via url in this format to checkout or cart ...com/checkout/?add-to-cart=632:11,422:7
    function add_multiple_products_to_cart_9R_M2asdf() {
        // Ensure WooCommerce is installed and the 'add-to-cart' query parameter is present and formatted correctly.
        if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
            return;
        }

        // Empty the cart before adding new items otherwise it just adds to the ones added before...
        WC()->cart->empty_cart();
        
        // Remove WooCommerce's default add_to_cart_action hook.
        remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );

        // Split the product IDs and quantities.
        $product_entries = explode( ',', sanitize_text_field( $_REQUEST['add-to-cart'] ) );

        foreach ( $product_entries as $entry ) {
            // Split each entry into product ID and quantity.
            list($product_id, $quantity) = array_map('absint', explode( ':', $entry ) + [null, 1]);

            if ( ! $product_id ) {
                continue;
            }

            // Set the quantity in the request.
            $_REQUEST['quantity'] = $quantity;

            // Handle the final item using WooCommerce's default method.
            if ( end($product_entries) === $entry ) {
                $_REQUEST['add-to-cart'] = $product_id;
                return WC_Form_Handler::add_to_cart_action();
            }

            // Process the product.
            $product_id = apply_filters( 'woocommerce_add_to_cart_product_id', $product_id );
            $product = wc_get_product( $product_id );

            if ( ! $product ) {
                continue;
            }

            $add_to_cart_handler = apply_filters( 'woocommerce_add_to_cart_handler', $product->get_type(), $product );

            // Handle different product types.
            if ( 'variable' === $add_to_cart_handler ) { // Variabl Products
                woo_invoke_private_method_93gK_M3q( 'WC_Form_Handler', 'add_to_cart_handler_variable', $product_id );
            } elseif ( 'grouped' === $add_to_cart_handler ) { // Grouped Products
                woo_invoke_private_method_93gK_M3q( 'WC_Form_Handler', 'add_to_cart_handler_grouped', $product_id );
            } elseif ( has_action( 'woocommerce_add_to_cart_handler_' . $add_to_cart_handler ) ) { // Custom Handler
                do_action( 'woocommerce_add_to_cart_handler_' . $add_to_cart_handler );
            } else { // simple product
                woo_invoke_private_method_93gK_M3q( 'WC_Form_Handler', 'add_to_cart_handler_simple', $product_id );
            }
        }
    }
    add_action( 'wp_loaded', 'add_multiple_products_to_cart_9R_M2asdf', 15 );
    /**
     * Invoke private method of a class.
     *
     * @param string $class_name
     * @param string $method_name
     * @param mixed  ...$args
     * @return mixed
     */
    function woo_invoke_private_method_93gK_M3q( $class_name, $method_name, ...$args ) {
        if ( version_compare( phpversion(), '5.3', '<' ) ) {
            throw new Exception( 'PHP version does not support ReflectionClass::setAccessible()', __LINE__ );
        }

        $reflection = new ReflectionClass( $class_name );
        $method = $reflection->getMethod( $method_name );
        $method->setAccessible( true );

        return $method->invoke( null, ...$args );
    }