can you tell me what engine size and fuel type this is please?
also do you have any check engine or other fault lights on?
OK if the box is switching to manual every time you stop then check that its not in sport and if thats OK then I'd ask the dealership to ensure that the latest software is loaded into the car
if you have any lack of power or fluctuating engine speed at idle then its possibly a vacuum leak on the engine
let me know what you find
do you still need help?
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