I rented a car using my bunq card (which worked flawlessly) upon arrving to retrieve the car, I had to pay (with my card) a gas fee to ensure that if the car wasn't returned with full gas the car rental company could deduct some money.
During payment I specifically used dual-pin so it would take the payment from my Main sub-account. This worked. After returning the car, 2 days later I received back the money. Unfortunately the money was received on my sub-account public transportation. It would be great if bunq system automatically recognises the previous transaction and would understand hey this is a return / reserved amount and since initially it has been payed from the main sub-account, let's return it in the main sub-account.