Stick up Cam recording length

I have a Stick up Cam and have the video recording length set to 120 secs but when I view the history to check on recent events I am noticing a couple of issues.Firstly, motion is detected when i leave the house and get into my van on the driveway, once the van door is closed the recording stops which is fine but a few seconds later when the van drives off there is no further detection.Secondly, a car drove over my front garden, reversed back off and pulled into the road, the car door opened and... no idea as the recording stopped! Am I missing a setting somewhere?Any advise welcome