Power trunk opening by it's self
I've got a 2015 MKZ Hybrid with the power trunk option that the trunk opens by it's self sometimes.
I will turn the car off, get out, shut the door, open the trunk (using the dash button or button by the license tag) to get something out, shut the trunk using the button by the license tag, wait for it to close then touch a door handle to lock the car, then I get 2 short beeps of the horn & the trunk opens by it's self.
Is this Normal? a newly found enhancement or bug?