Lightning detected when none around lately

My Weatherflow Air unit has recently started alerting Lightning within x miles of home several times a day and then nothing - even when there are no storms within 400 miles. It never used to do this. I don’t see any evidence of electrical equipment arcing anywhere nearby and the times seem pretty random.

The location of the Air unit has not changed in more than six months.

turn on an am radio and tune it to an empty spot. It might help you locate the source.