Birders

I am fussy about location data, so I deny it in settings, and allow "once" each time it launches, and then it shares what bird packs are installed. Did you get that start-up dialog? Did you enable location data in "settings"?

If you did, then who knows what .... normally, if it doesn't use GPS (I don't know if it does) then a very close result comes from your ISP
s lines. Most networks are well known and your IP address says a ton about your location.

Cellular data? I have had interesting situations come up where an app or store guesses my location when I am on cellular data as some hub from the celllular provider, hundreds of miles away.

Interesting.
Maybe there are notes at Cornell that will help.