Doors Not Locking When Locked With Remote

It was by accident that I discovered that the front driver door was not actually locked on my 08 G8 GT. I was in a hurry and just opened the door without using the remote. Yes, it opened causing the alarm to go off. A few days later my daughter opened a locked passenger side front door causing the alarm to go off as well. Has anyone else had this happen? I never noticed this before as I always unlock the doors with the remote. I am now going to have to check the doors by hand to see if they are actually locked.