Hi Marcus, and welcome to the Club.
Given your short trips, this is not surprising. The battery needs to be fully charged for stop start to work, and at this time of year we tend to be using our wipers, lights, climate control fans, heated windows etc a lot, not to mention the additional power required to start the car, so lots to drain the battery.
So my guess is that it is nothing to worry about. However, if you bought with a warranty you might as well get it checked, given that you have had it less than a month.
Enjoy both the car and the Club!