If this is your first Range Rover, you will need to get used to the way they handle ( or not as the case maybe)
Even though you say you have the right pressures, they are picky and you'll find different tyres and different rangies all have their own sweet spot with regards to what pressures to run, so it could be a game of trial and error.
My DSE preferred 34 on the rear and 30 on the front until i changed tyres and then she seemed to like 32 and 28 .....
Range Rover steering is often debated and they can wander and tramline with great regularity, but you dont want the much lamented 'Death Wobble' which is when the whole thing wobbles about after hitting a minor pot hole or drain cover.....
As above check the steering damper, and also check your steering joints too.