Sudden Death of Freelander

Hi all, need some help
My Freelander 2 went into the dealership due to a noise when turning left. It resulted in a hefty bill replacing the rear driveshaft a new diff and the haldex unit being flushed
The car was then cleaned and awaited collection so far so good and I paid the bill no issue here
BUT:
On day of collection the car was moved to front of dealership and then wouldn't start following it, with key stuck in ignition
Dealership have run tests and say that the fuse box is getting power but not outputting any (They did disconnect the battery when doing the work)
They are now talking of replacing the fusebox/loom but say its on back order and could be months. Also stating that each is unique to the vehicle so cannot source one from a second hand dealer/ebay
So any thoughts on this latest issue?
Could it be a fuse output issue? any thoughts on how to fix?
Has anyone else experienced this?
Could they check anything else?As the diagnostic box is just showing error with no code the Output issue has been discovered manually.
Mechanic is 25Year+ LR expert but may never have come across this
So as I said the car did drive to front of dealership and then refused to start and I cannot explain why it first drove then didn't nor can they after two days of checking it out. Really trying to avoid another hefty bill if their option isn't the solution
Any help welcome

Battery condition would be my first item to check. These vehicles need a perfect battery, or issue arise. Next I'd be checking the battery leads, as they can be marginal, then just fail.
The key stuck in the dock suggests it's a power issue.
With the battery disconnected, try re-seating all the plugs at the CJB, as these can get knocked by feet.