Power tailgate opens randomly

On a number of occasions, I have returned to the car (2018 L&K 280 estate) to find the power boot standing wide open. It has happened when parked at home, in supermarket car parks and multi-storey car parks.

At first I thought I must have accident pressed the open button on the key fob, but this is not the case.

This happen to anyone else? Last time was very annoying as it was open all night and drained the battery as the interior lights were on.