Yeah I had no idea until it happened to me. Luckily it was at the tire shop and not out on the road with a flat.All the car companies are using those these days and if you search youtube there’s tons of videos on these swollen nuts.
The nuts are hard steel with a pressed on outer stainless cover and they rust between the metals and swell up.
Most lug nuts are either 3/4 (19mm) or 13/16 and most of these swollen lugs will come off with that next bigger size socket but, there is that one last tighter one that the corners just round off and people need to use the right size before it only gets worse.
I just use the extreme force method in the video I posted. Those nuts need to be replaced anyway.
I don’t know why anyone would put the same nuts back on?
Actually, I do know, it’s because they were lucky that they came off in the first place without stripping and they don't understand what is going on.
If you take off the nuts and every one of them was stuck even slightly in you socket, they are swollen.
Some day you will get a flat on the road and wonder why your tire iron won’t fit on your nut.