I used to have a P38 Range Rover and when I took ownership, it came complete with swollen wheel nuts, which were completely evil to remove, so I replaced them.

My FL2 HSE also suffers from this - in fact I've just replaced 10 of the damn things, so I can get a 21mm socket on them again. It was only £30 for 10 (non genuine but identical).

Now I think I know what happens. The steel corrodes under the stainless top "sleeve" and the nut changes from 21mm to 21.5 or thereabouts. Someone had struggled to get some of mine off and chewed the top of the hexagon, so it was time to replace them.

But, I've mentioned this to a few garage mechanics (even an JLR main dealer) and they say "Not heard of that one". Yet I've had it twice! Is this a Land Rover only thing? Life is an uphill struggle. Only the gradient varies.

It's VERY common on a Freelander 2. So much so, that I included it into this video of 5 top tips for your Freelander 2 which you can see here .

 https://www.youtube.com/@scottandalana4x4
https://www.facebook.com/ScottandAlana4x4

happened on my disco, got fed up with buying bigger sockets but it failed MOT so badly with body rot that was the least of it issues so got rid all together  Range Rover L322 (the current posh one)
Discovery 2 (just gone)
Discovery 1 (long gone)

It's happened to me. I bought a bag of 20 replica ones and have changed them as the old ones start to look bad. I've still got a few left. Not bad for 9 years of ownership.

I did the same, I have half a doz left but may need to swap 5 on one wheel next time Im working on that corner,

Changed all my nuts for aftermarket ones within the first 2 weeks of getting the car. Some of them were so bad that even a 22mm socket didnt fit...

Nothing more annoying than swollen nuts

All my Jag x types have had the same problem as well as my freelander. Either pull the covers off the nuts and use a 19mm socket, or buy a set of aftermarket.