Hate to be a pain but having been through all previous posts I cannot see one that describes my problem.
When I first start up the menu screen comes up but when I touch it it goes blank. After about 15 minutes traveling the satnav screen comes on and It works perfectly for however long my journey.
It does this every time almost as if it is engine temp. sensitive or something, any ideas appreciated. 🤔

No expert but I would suspect a dodgy connection.

First thing I tried, all connections seem ok. Funny thing is it always starts up after about 15 minutes then works perfectly.

You say that when you first start up that the screen comes on but then goes off when you touch it. What happens if you don't touch it, does it stay on or does it go off?

Hi dennij,

As soon as I turn on ignition I get the Land Rover logo then the home screen (see photo). That screen remains on if I do nothing. If I touch Navigation then it just goes blank.
After about 15 minutes driving the home screen comes on again and then if I touch Navigation it comes on and works fine. Does this every time. I checked under seat plugs which all seem ok and like I say, once it comes on it stays on for entire journey.

Click image to enlarge

Looking at it I would say that it's unlikely to be a connection that's failing to the unit as it doesn't fail again until you switch off, it sounds more to me that the issue is with the screen or the unit in that it only fails when you press it. The screen works in a similar way to your smartphone in that there is a digitizer of some description that creates a circuit when pressed, why this doesn't fail again once the unit has been on for some time though is odd. Someone more technical may be able to give a more informed response but this is where I would be looking.

On Gen 1 touchscreen is there a setting for time out "return to home screen"? Ie if you are in a sub menu and you don't touch anything after a set time it returns to home?
If so it sounds like the touchscreen is doing this as its not receiving any signals from the nav module.
Check and reseat all connections on the back of the touchscreen.
Failing this it sounds like the nav is not receiving a CAN signal which means there could be a fault with the touchscreen. The Touchscreen is the gateway module for the MOST network.
I would suggest you refer to the workshop manual in topix for your MY and follow the diagnostic procedures outlined for this fault. There is a diagnostic menu in the screen which can be accessed which will be outlined in the workshop manual. This may also point you in the right direction.
Otherwise connecting to SDD will tell you straight away the fault. MY15
Tyre Pressure Monitoring System (TPMS)
Surround Camera System
InControl Apps soon to be replaced with CarPlay (WIP)
Meridian Premium Surround Sound
Digital Audio Broadcast
Timed Climate
Cruise ECO Data
Follow Me Home Reverse
Extra Features Menu
Picture In Motion
4x4i screen (WIP)
Digital Broadcast TV
Meridian Rear Media with WIFI
Factory Powered Tailgate
Blind Spot Monitoring (BSM)
Reverse Cross Traffic Alert (RCTA)
Electrochromatic Wing Mirrors (WIP)

Thank you both, it's at least given me some more things to investigate. I will start by checking the connections to the screen which I haven't yet done. Will post my findings.

If you need a screen I have one for sale at £45 and if you are near you could always come and try it!

Thanks, I'll keep that in mind

Well there you go guys. Thanks to 3disco it turned out to be the touch screen all the time. Plugged in the replacement and it's working as it should.
However, thanks to all for the past advice as I really needed to check everything else, so it became a process of elimination.