That's the puzzle you see - it doesn't do automatic lane change when you are driving in AP (which I think comes with EAP?) and under options it doesn't say EAP. What it says is "No battery performance" (what does this mean incidentally?) and $APPC. A quick google search on $APPC leaves me none the wiser - there are a couple of forum postings basically asking the same as me - what does this mean but no categoric answers. If you can tell me that would be great.
Pretty sure ‘No battery performance’ means it’s not a Performance model or doesn’t have launch control etc, that’s normal if typically unclear. The $APPC I’ve never seen before and, yes, auto lane change with Nav on AP is an EAP feature.
The fact that the upgrade price is £5.8k, which is the new full FSD cost, suggests to me that your car had an EAP trial, the owner didn’t buy it but Tesla forgot to turn it off. For a tech company their systems are often very poorly implemented and I have heard of this type of situation before.
I’m afraid I’m out of ideas