FOX - WooCommerce Currency Switcher Professional

Plugin URL: https://woocommerce.com/products/smart-coupons/

In file woocommerce-smart-coupons\includes\class-wc-sc-purchase-credit.php add next code:

if (class_exists('WOOCS')) {
    global $WOOCS;
    if ($WOOCS->is_multiple_allowed) {
        $currrent = $WOOCS->current_currency;
        if ($currrent != $WOOCS->default_currency) {
            $currencies = $WOOCS->get_currencies();
            $rate = $currencies[$currrent]['rate'];
            $cart_item_data['credit_amount'] = $cart_item_data['credit_amount'] / $rate;
        }
    }
}

and in file functions.php of the current wp theme add next code:

add_filter('wc_sc_credit_called_price_cart', function ($price, $args) {
    if (class_exists('WOOCS') AND $price > 0) {
        global $WOOCS;
        $price = $WOOCS->woocs_exchange_value(floatval($price));
    }
    return $price;
}, 10, 2);