V1 Not Picking Up Radar By School

So this has happened to me a few times, I tend to drive by one of the schools near me that has a "Your Speed Is" sign, and of course it displays my speed however my V1 will remain silent, not a single alert or detection. I don't know why. Yes it functions properly (I hope so) and no there is nothing blocking the V1's line of sight. So what gives??

Most likely it's an FM (Frequency Modulated) signal emitted by the Speed Sign rather than the normal CW (Continuous Wave) signal that almost all radars employ.