my 2013 Lexus ES 350's driver's side lock will not lock when using the wireless remote or the Smart access system. All of the other doors function well except the Driver's Side. Note: It will unlock using all functions available, just not lock...When I manually lock it, it seems to be harder to lock than the other doors. I see the lock trying to lock but can't quite make it. It's like it's stuck

 

Probably needs some grease in there to lube it up. Or the push rod is bent. It's fairly easy to take off the door panel to see what is going on.
On the worst case scenario the actuator might be going bad and need to be replaced. Would be unusual on a car that age.

 

Try disconnecting the negative battery terminal, wait 30 seconds, and reconnect. This will reset all sensors and actuators, in case one is stuck in a certain position. If that doesn't work, then there is no choice but to open the door panel to observe it, as suggested above.