maybe the camera got someone else. I have not experienced this yet and I always pull up to the white line because on quite a few of the lights they will not change unless the sensor in the street feels the weight of your car. I see many people sitting a meter or more back from the white line and sitting a long time until someone else sets the sensor off.

'Tis better to be silent and be thought a fool, than to speak and remove all doubt

Abraham Lincoln