That's odd. I think that either you have passive keyless entry (all doors open from any point of entry when you touch the door hande with the key in your pocket) or you don't (you need to use the remote button to unlock any door, like the Evoque loaner I had a few weeks ago.) Don't know if certain LR4 trims didn't come with passive keyless entry back in 2012, but if your driver door unlocks passively without the key, so should the 3 other ones IMHO. Do all door handles include the little rubber button / sensor? Does the car lock all 4 doors when you push that button - regardless of the door you use to lock them?
Do you have single point of entry or multi point of entry mode enabled? Try switching mode around with the remote. It shouldn't make any difference as far as passive keyless entry is concerned, but worth a shot. Otherwise I tend to agree with Axel that something is wrong with the sensors or central locking system and you should get it checked out.