Disable WooCommerce's Shipping Rates Cache

diable_wc_shipping_rates_cache.php

// essentially disable WooCommerce's shipping rates cache
add_action('woocommerce_checkout_update_order_review', 'clear_wc_shipping_rates_cache');

function clear_wc_shipping_rates_cache(){
    $packages = WC()->cart->get_shipping_packages();

    foreach ($packages as $key => $value) {
        $shipping_session = "shipping_for_package_$key";

        unset(WC()->session->$shipping_session);
    }
}