ProxyPay issue (no error message on declined card)

I’m using ProxyPay3 for payments (redirecting to the bank).

Unfortunately, when a credit card is rejected, the client is redirected to the “nok” URL (which points to payments/proxypay3_nok.php) and then redirected again to the shopping cart page. This is definitely wrong, there is no error message that the transaction has failed!!!

Any help would be appreciated.

Thank you.