2012 prius c proximity sensor

Hey guys...I'm new here to posting but have been surfing these forums a bit. I have the prius c 3 with proximity door lock/unlock. The issue I have currently is when I come up to the car, the lights come on as it senses my key fob, and I can unlock the doors with just my hand. When I go to lock by hand, it does not acknowledge. I tried one finger, two fingers, back of my hand, sideways, vertical...nothing. One time I got it to lock by watching the Toyota video then doing the one finger touch. I can't since get it to repeat it. Any thoughts? The remote works when I press the lock or unlock button.