Update:
Still an issue, the
dealership identified that the battery coding had a typo in it and one digit was wrong, they have since "fixed" that - they took it on a test drive and it did work once (proven by dashcam) they took it out again the next day and didn't even attempt to use the stop/start - it comes back to me - same issue.
Now I have a lot of dashcam footage of them "working" on my car, at one point they suggested their colleague that looked at it last time didn't even try anything or test it and also their "master tech" hasn't done the stop/start course and didn't know what the readings meant.
It's now open with the finance provider (FP, (blackhorse)), looking more towards rejection at the moment as the
dealership has had 3 attempts at fixing it. FP are now getting an independent to look at it to get the ball rolling for rejection.