Issue with updating checkout AJAX Shipping

If you try to change “Comuna” (which is like state) if freezes and throws the error

I’ll give you admin access. That is staging site, so you can change whatever you want.

I’m so sorry. I created them on my local dev site.

Now this should work.

Sorry guys. Now it is 🙂

It works, but the plugin indeed that I need for this to work isn’t.

I think the problem was that locally I have PHP 5.6
On my server I have PHP 7.1

On the logs I’m getting this error:
name was called incorrectly. No se deber\xc3\xada acceder a las propiedades del producto directamente. Backtrace: require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, WC_AJAX::do_wc_ajax, do_action('wc_ajax_update_order_review'), WP_Hook->do_action, WP_Hook->apply_filters, WC_AJAX::update_order_review, WC_Cart->calculate_totals, WC_Cart_Totals->__construct, WC_Cart_Totals->calculate, WC_Cart_Totals->calculate_shipping_totals, WC_Cart_Totals->get_shipping_from_cart, WC_Cart->calculate_shipping, WC_Shipping->calculate_shipping, WC_Shipping->calculate_shipping_for_package, WC_Shipping_Method->get_rates_for_package, WC_Shipping_External_Fetch->calculate_shipping, WC_Abstract_Legacy_Product->__get, wc_doing_it_wrong. This message was added in version 3.0., referer: http://sensacional-store-prod.us-west-2.elasticbeanstalk.com/checkout/

I know this is out of scope with the plugin. But could you please guide me a little bit on where should I fix this? Fortunately the plugin only has 2 files.