FOX - WooCommerce Currency Switcher Professional

Plugin link: https://woocommerce.com/products/facebook/

Insert next code in file – \wp-content\plugins\facebook-for-woocommerce\includes\fbproductfeed.php:

if (class_exists('WOOCS')) {
    global $WOOCS;
    $currrent = $WOOCS->current_currency;
    if ($currrent != $WOOCS->default_currency) {
        $WOOCS->reset_currency();
    }
}