ALP failed

[gatodrunk]

Hi:

If somebody can explain me what happened:
Today I was driving back home when my ALP and my radar (StiR plus) started to beep both at the same time notifying a laser alert. I adjusted the speed to the posted limit in less than 4 seconds (50 KMH I was driving at 75) and I calculate that I was targeted from 200 to 300 meters away.
OK I hadn't see the officer so I tough everything was fine. Suddenly from one truck that was parked in a driveway the officer showed up an made me stop and told me the exact speed that I was driving "75 Kmh".
Off course, nothing to say just I received my ticket.
Now, why this thing didn't work this time? I have the last firmware 5.1.2, I have two sensors in front of a medium size car (Hyundai Santa Fe 2014) both working OK at least as parking sensors.
I have my system with the bluetooth adapter connected to an Android phone (app up to date).
Distance between sensors is 25 inches.
This set up had worked against 2 other alerts with no problem.

I attached the use and settings statistics if somebody can see anything that is not right.

Thanks for your help.