functions.php to force billing

Hello, i buy your plugin and it seams have some bug.

Here is video: https://easyupload.io/ssc9uy
As you can see. All countrys are in EUR, only Serbia is RSD. Tried changing all settings, etc, not helping. Its like ajax woocommerce not working properly, its not force currency price on changing countrys. I deactivate plugin for now, its live website. I used on other site similar plugin and they used this code:

add_action(‘woocommerce_checkout_update_order_review’, function($data) {
global $WOOCS;

if (is_string($data)) {
parse_str($data, $data);
}
//***
$_currency = $WOOCS->get_currency_by_country($data[‘billing_country’]);
if (!empty($_currency)) {
$WOOCS->set_currency($_currency);
}
}, 999);

Do you have something similar. Also checkout not use any cache.
Thanks