To be precise, I suspect your AirTag is reporting a “last known” location.If it’s intact, and still identified as yours, it would display a “low battery” graphic adjacent to its record in your “items” list, and in my own experience it does so for at least a few MONTHs before becoming exhausted (at least with the Panasonic CR2032s used by Apple. It’s possible that it fell out or was removed from your bag, was picked up by someone and pocketed, and that the person who did so then was alerted that it was moving with him or her. He could then have reset it, paired it with something that belonging to HIM and now has more personal security.
I have a story and related AirTag question. The last time we traveled (in the US, going through TSA security at a major airport, the agents insisted that we remove anything with metal in or on it from our service dog and that we have her pass through the metal detector alone. As she did so (and at first we were amazed that she even was willing to do that, because they wouldn’t allow one of us to send her through and the other to position on the other side to receive her), the “next-door” metal detector alarmed, terrified our dog, and she sprinted off down the terminal hallway (LONG hallway) wearing no ID whatsoever.
Fortunately, her escape was witnessed by a very kind flight attendant, who managed to catch her and bring her back to us. That didn’t really trigger any more compassionate behavior by the TSA people, but we still managed somehow to get her through.
Later on the same trip, her AirTag fell off her collar because the stalk of its receptacle broke. It was paired to my spouse’s phone, and she was not accustomed to checking on her devices. We didn’t notice that one trinket was missing from her heavily adorned collar for a month, but when we did, FindMyt told us it was resting near a bush in a park 1,000 miles away in Las Vegas where our great granddaughter’s first birthday party had been held. It’s no longer there, or perhaps IT’S battery bled to death without us noticing it. Typically, it won’t alert passersby unless it’s reported as “Lost” by its owners or unless it becomes “attached” to someone, intentionally or unintentionally (peripherally related story available on request)
A related airport question is whether there’s enough metal in one for it to trigger the metal detectors all by itself. And, getting pretty far afield here, does any reader know of collars, vests, or leashes that themselves contain no metal clips, so that we could get her through the detector more safely on our next trip?
And, as regards the thoroughness of airport security checks, they’re all over the map. I’ve seen expensive water bottles taken from passengers because they were a bit too large, and at the other extreme is a YouTube video shot by a couple who were moving from Florida to Canada and had to ship their two dogs by air, in cargo. They used FAA-approved travel kennels, but just before turning their pups over to security they taped GoPro cameras into each kennel. When they retrieved their dogs, the cameras were still taped securely in the kennels. Of course the batteries were exhausted, but they had impressive movies of the dogs’ tenor while in the baggage holds and NO evidence of any look into the kennels by the security folks. And these were placid little pups, not aggressive Pit Bulls!