Disco 3 (LR3) Intermittent suspension fault

My disco 3 has a suspension fault and I'm looking for some help/ advice.
On a few occasions now when driving on motorway I get 3 orange lights on dash and message normal height only and the lights on the centre console for height adjustment go out and I am unable to adjust suspension height, if I stop and turn off engine and re start and drive all is good for anything from 15 miles to 150 miles before it happens again.
I've been told it's the tracking that's causing it, the car pulls slightly to the left but nothing bad
Any ideas of where to look?

Need fault codes, otherwise it will just be expensive guesses.
Icarsoft is the cheapest reader kit, and is pretty good, 100 quid.
IID is the best non lr reader, and is the dogs whatsits, 500 quid!

Tracking causing air suspension faults I do love a good laugh.

Best get under the car and check your air suspension pump and hoses