There are a lot of conditions required before start stop will work.
Does this error give you any indication in the car manual what is wrong with the start stop tech?
If so go back to the dealer.
I personally switch off start stop tech every journey, as there are more dissadvantages than advantages.
I never use it, and never wanted it.
1....A few drops of petrol saved. Maybe.
1...Wear on engine over a period of time.
2...Reduced life on car battery (even if heavy duty start stop type battery), from at least 7 years down to 2 or 3 years.
Many car forums (all makes) complaining about needing a new battery in just a few years of use.
3....The danger of being at a junction or traffic lights with engine off, which increases your start time to get out of a possible dangerous situation..It could be life and death.
4...Accidental operation of start stop in the middle of a junction cutting off the engine, seen that many a time, where owners have to restart and get out of the junction before being hit.
So as you can see, we car owners have got landed with a dangerous and unwanted tech, which we would be better off without. (my opinion, though the above confirms we are far better off without start stop tech)
You can argue the case if you want to