Originally Posted by JeepersCreepers
maybe the sensors in one of the handles is bad, constantly detecting a hand where there isn't one, and once you get in range it finally unlocks.
That almost certainly is the issue.
I wouldn't be surprised if you could play with either of or one of the front door exterior buttons and have the system fight you when you try to lock it that way.
It's likely a bad door handle sensor in on side or the other.