I’ve not had any problems with the electrics (proximity key and audio) up until a recent service by a dealership.  Now, I can’t guarantee how I’ll unlock the car, I’ve had to resort to the emergency key on more than one occasion.  The audio and map visual will often switch off and back on again.

is it worth taking into a different dealership or should I consider an electrical mechanic?

It may be a coincidence with the service being carried out around the same time.
However, it does sound like a battery issue, worth having that checked first