Network CAN Bus-software?

Everything works fine until you disconnect the battery or you let the battery get low/flat, on the display it shows N (neutral) all the time, You can watch a film while moving (in the front) and when you put it in reverse display still says "N"
Now before proceeding and you advise me on things, please be advised I AM an Auto Electrician, also let me point out the reverse lights come on and the parking sensors work! But no camera no gears showing only "N" there is no black screen it's just as if you are not in reverse.
But after about 500/1000 miles it starts working fine until next time, now again before you reply I can tell you it is not! The gear box switch, camera, charging system or battery I know all about that with Range Rovers I even own a proper Land Rover diagnostic (dealership software) not some rubbish OBD code reader from Ebay.
I suspect its ether a software glitch or a dodgy Body Control Unit (BCU) do you think this could be the case this is the Question? Have you heard of this before?
Most places where you explain the fault, they just come out with annoying stupid suggestions like have you tried a new Battery E.T.C. As I explained it's a strange fault it's not even a bad or loose connection because it only happens if say the suspension plays up and you reset it by disconnecting the battery. If I use a full vehicle reset with the laptop that does not cause the problem strange! What do you think?