Just got HW3 last Thursday and notice when I'm driving not on AP, and when I signal (leave the blinker on) to change lane and see a car next to me the screen doesn't show the red lines anymore.... I see the car on the screen and in my blind spot but the red lines aren't there... Out of the blue it will show up but that's more like once in like 2 days I see the red line. Is there something that might be wrong w my sensor?