When waiting at a light (at a complete stop) and usually with an incline, there is a jerk. There's no movement from brake to gas pedal. No movement at all. Foot on brake. But while waiting at the traffic light, it feels and sounds like someone from behind has bumped the back of my Envoy. I'm not sure when this started but it's more of a nuisance at this point. I've read other people's experience on different forums but no solution. Is there one or at least a recall to fix the "problem"? Thank you.