FOX - WooCommerce Currency Switcher Professional

Plugin link: https://wordpress.org/plugins/food-store/

In file wp-content\plugins\food-store\includes\class-wfs-frontend.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'];
            $total_price = $total_price / $rate;
        }
    }
}