This happened the first time to me today so here some background:

I switched Audible to charge from a bunq virtual card but I got the expiry date wrong (and Audible apparently can’t verify that date). So they tried to charge my monthly Audible subscription which was denied by bunq since the supplied expiration date was wrong.

I fixed that fault on my part but what surprised me is that I did get no notification from bunq at all.
I have all notification toggles on but no push, no badge, nothing. I only noticed the denied payment when I checked my events for a completely other reason.