LB1985

I got a 2016 Rapid Spaceback 1.2 DSG just over a week ago to replace my previous 2014 Seat Leon DSG. My driveway is on a slight incline. The other day, I put the car into 'park' and briefly took my foot off the brake as I was about the apply the handbrake. I was shocked that the car rolled forward picking up momentum - it wasn't just a few inches. I've tested the same in a few different locations and the same happens. I always apply the handbrake anyway, but am concerned that the DSG selector being in 'park' does not provide the secondary protection I thought it should. Also, my Seat Leon DSG did not do this (and also had a traditional handbrake). Is this normal? It doesn't seem as though it is to me. I've been in touch with the dealer who so far have told me to try with the ignition off and see whether it happens too - which it does. Any insights appreciated!