K-wing bees at the entrance — are tracheal mites still a thing, and how would I even check?

Uppsala, third year, four hives. The last few days I've been seeing a handful of bees on the landing board of one hive with their wings held out at odd angles — the front and back wings unhooked so they make a sort of K shape. They walk around, sometimes try to fly and can't. Maybe ten a day, not hundreds. I did a search and every older book says K-wing = tracheal mites, Acarapis woodi. But nobody at my club has ever mentioned them and my mentor sort of shrugged and said "that was a 1980s problem". My varroa wash three weeks ago was 2 per 300 after Apiguard, so I don't think this is the same thing as the deformed-wing posts. So: are tracheal mites still around in Europe? Is K-wing actually diagnostic for them? And is there a way for a hobbyist to check, or is it a lab job? I don't want to shrug at something just because my mentor does.