Lufthansa Says Passengers Can’t Use Apple AirTags to Track Checked Bags (nytimes.com)

This came up before: the translation implies the person doesn't know what an airtag is and just read them the standard "all electric devices must be turned off when stowed" policy.

other than active blocking what can/could they do to stop it?

Every time my luggage was lost I knew where it was - it was just the airline that disagreed with me.