Normal squawk, maybe learning to drive? Trouble intercepting the localiser maybe?
There's ham repeaters around too, and lots of oddball data networks etc. Probably trunked comms around too (not a ham but work in that field).
I think it would make sense for the feds to have backup comms in case the shit really hit the fan, so maybe some are trained up?
Not conspiratorial I know, but a possible explanation.