If your driveway is steep and downhill, as the drive levels out and the van is still pointing down hill, the front radar sees the ground as an obstacle and engages the city brake function. It's quite common on lowered vans.
You can turn off 'front assist' in the settings menu. It's all in the handbook. However, should you have a bump and it turns out that you have turned off a safety feature, you might have a problem. Thank you for reply