In a collaborative effort, Apple and Google have developed an industry-standard detection feature called “Detecting Unwanted Location Trackers” (DULT) for Bluetooth trackers. This standard allows users on iOS and Android devices to be alerted if an unknown Bluetooth tracker is monitoring their location.
That is how it works. Unwanted tracking notifications only trigger if separated from the owner for some time. It’s possible the paired iPhone was drained or had Bluetooth disabled which would cause the tracker to think it’s separated.
I bought airtags for my luggage and keys, but they’re registered to my iPad which is not my EDC device and is large. My main device is an Android. If I don’t take the iPad with me, eventually my Android will pop up with an “unknown tracker following you” message. The message iets you ring it to locate it, but nothing else. The annoyingest thing is that i cannot tell the android phone it is mine and known, and please stop pinging me about it.