Broken door handle sensor?

I LOVE comfort access in my X5, but I think something is wrong with my rear driver side door handle. If I put my hand on any other door, all four door lock/unlock. With the rear driver side door, it opens all other doors except itself. When I put my hand on the handle, I hear the door lock actuator attempts to unlock the door, but never unlocks it.

Is there a setting that I can change, or do I actually have a problem with the car? Everything else works well