Posti LOST my package, but I WAS TRACKING it the whole time
Early in the year I sent letters to the president and prime minister of Finland, each envelope had a gps tracker ("Apple airtag"), long story short: I got a reply from the president's office and they send the gps tracker back, but Posti lost the tracker (Posti is the finnish postal service).... but because I could track it I knew where it was and decided to go get it myself after doing a little detective work.
Was it entirely Posti's fault? I don't know, but the item went to Posti's central office directly to Lost & Found...
If you want to buy an AirTag and do your own experiments: https://www.apple.com/airtag/