I had this call just now aswell, it really took me some time to figure this was a scam call. They call from a private nr.
He knew my name and last nr's of my bank account. He asked if I had an Android or Iphone, and wanted to install a virus scanner from Bunq
When i refused they said they would limit my bunq account.
I told them that without any verification they wont get acces to anything, he said they could call from a 088 nr but i was not allowed to pick up, and that they were not allowed to communicate trough the app because it is a fraudulent case.
Luckily i have had an call from BunQ once before where they only asked me if i made a payment to Spain and when i said no, they said OK we will block it and that was it. (altough i know am doubting if that was a real call)
So i said the same to this man, and he kept pushing quite agressively, asking "what did i found so weird about the situation". I decided to hang up. They called back immediately, i hung up and that was it.
This really had my heart racing, it's really more sophisticated and it would really help if Bunq made clear how they communicate...