Margaretha-Blue-Butterfly Right, so the app doesn;t say your card isn't right but only says the transaction failed.
Did you already make another cash withdrawal today? There's a 500 euro limit per card per day. This limit is set by bunq and you can't change it. In the past you'd get a message about the limit in that case, but perhaps that has changed.
Perhaps it's better if you ask bunq support, they should be able to tell you more about the cause why it was refused. You can find them here: https://go.bunq.com/link/support
I've got the feeling we're playing a guessing game here. I'd like to know what was the problem anyway :)