I am not a mechanic but google is an interesting way to diagnose problems being a non mechanic when its battery/fuses/immobiliser mean yes it is an electrical fault something and our attempts to diagnose it where a failure.
So an human expert was sought, youtube is an interesting place although some solutions seem per year model and i guess wont work on a older or newer versions
On refection It appears that our battery charger does not work, and the battery was the fault from a second opinion despite having enough voltage to switch on most electrics.
The cars guide book was also vague when it was consulted on what it could be so nobody came out a winner being not a ‘please insert the forth wheel’ obvious fault…
A car that cannot start but powers up instruments is almost a paradox, and it appears one issue more will be seen of by many.