There have been instances where I would be driving and the V1 would alert to an approaching X or K band door opener to the front, then the sides (as I pass) and then the signal vanishes without a rear alert after I pass the radar source. My V1 has a clear view of the back window. I have noticed other sources being reported to the front, sides and rear as I pass, but not every time. Is there something wrong with my V1? Or does this have to do with signal strength (or lack thereof) from the door openers.