Have you tried resetting it?
When I received my car, the setting was set your way and I had the same issue. I switched the setting when I opened the trunk to unlock the doors and executed it. Then I reset it back to leaving the doors locked. The problem was solved and I never had a problem since.
I have been fortunate, the car is now in its 10th month and that is the only issue I have had and I fixed it with this method. Now have over 15,000 miles of troublefree driving. I hope this "hard reset" works for you.