Over-sensitive emergency braking

I've been driving my new Octavia for a few months now and today it decided to trigger the emergency brake when I was reversing down my driveway. Now it is a reasonably steep driveway but the Octavia had happily allowed me to back down until today. I tried a few more times and every time it came to a sudden halt before it thought it was going to hit the driveway where it levels out.

I found there is a setting called "manoeuvre braking" which can switch off this emergency braking feature and is sticky so I don't have to do this on every trip.

I'd prefer to leave all the safety features enabled if possible – has anyone else had issues like this and found a better solution?

I did clean the car yesterday – maybe I cleaned it so well the ultrasonic sensors have a clearer field of view now ;)