Also inaccuracies in the car metering. On a short drive, the fullness decreased by 1% every 1.5ish miles. Parked, did my hour shop and found the fullness of the battery had increased by a per cent or two. (no I had not plugged into the Tesco chargers) Those 1 or 2 per cent soon vanished when I continued driving.A lot of short journeys is cold with no pre-heat while plugged in will cause a lot of loss. In addition I'm sure a lot of reports say the car losses a fair few % in the first few miles then settle downs. This might be down to it having to heat the cabin up and/or batteries.
However it won't hurt telling Polestar what you are getting both in car and calculated, then see what happens.