I haven't tried all of the stands/parking however stand 4 all of the ground vehicles and characters are sunk into the ground and I've just noticed that one of the baggage carts goes down to the roof? I do use GSX, could it be anything to do with this

Try to check if you have any scenery for the London area being streamed. I searched for London in my library in the sim and thought I had disabled everything but then when i searched for the World Update for United Kingdom I found more scenery for the London area being streamed that I did not know about. When I disabled those my issues with EGLC were fixed.

I've had a look but I can't find anything for the London area. I've disabled London by Orbx as it caused clashes. This is is between parking 3 and 4. If I use GSX, crew and passengers all have their feet underground and as I said the baggage truck nearly disappears. I'll have to see if it happens anywhere else

Hi,

Unfortunately not much we can do about that. EGLC is using a custom flattened platform to get around the crazy undulations in the base photogrammetry ground elevation. User and other AI aircraft correctly read the collision model of the custom flattened platform to set objects on top of it. The GSX simobjects however don't respect this custom platform, but instead sets their height as an offset from the base base photogrammetry ground elevation. There is about 1ft of difference in some areas, hence they appear slightly sunken.

A GSX profile allows to set custom elevations for the walking passenger models/paths, but not the base simobjects (like the vehicles, staff, stairs etc).

TL;DR just a side effect of working around badly deformed base PG elevations that can't be resolved via terraforming.

They should only be slightly sunk, not wholly at the stands. If that's happening, then likely some other mod is also affecting the underlying terrain elevation.