Freelander 2 Wont Start after flat battery

Hi Everyone,
I need a little advice/help please. Our Freelander 2 14MY was used before Christmas I left it standing for 2 weeks + on the drive and it wouldn't start.
As I was away from home partner called RAC. They couldnt get it going said it could be a wiring issue. I think they managed to turn the starter over via fusebox.

I fitted a brand new battery as the old one even when fully charged didn't solve it. I thought this would be the cheapest solution before more expensive fixes. Same result
Car has keyless Start you don't put the fob in dash. Same as Evoque I think.

On start with brake depressed Steering column locked is displayed and car shuts down.

On start without brake depressed multiple module errors ABS, Transmission, stability, Thermostat, immobiliser etc

Had zero issues with car prior to this radio dash etc light up.

The RAC couldnt get into the diagnostics so I'm thinking it may have gone into crash mode or a dodgy module is messing every thing up. Radio, doors mirrors lights all work as does the dash

Any help will be very much appreciated

Is it the same with both key fobs

Yes it is.

Think I found the issue I was looking in glovebox we have a mouse so its probably chewed the wiring up somewhere. It had made a nest in the door card, pooped on backseat. Explains the errors.

Highly likely cause isn't it . I have a poison bait box at the side of the fuse box.

Oh please don't use poison bait, it doesn't always kill the mouse but it is known to kill cats ,dogs, birds etc that can pick up poisoned mice. My bro used it in his loft and both of his cats died horribly of internal bleeding: use a Trip-trap instead with edible bait and you can easily relocate your mouse. Thank you.