Feel inside the ice maker tray and see if your feel ice cubes in all the ice cube slots.
Here's how to check it: Tape the emitter back so it doesn't block the beam. Remove the cover over the ice maker module and locate holes "T" and "H". Use a small piece of insulated wire bent in shape of a "U" and short T and H together. The ice maker should start a harvest cycle. As soon as the ice maker starts the harvest cycle, remove the wire. You may need to hold the door switch closed until the harvest cycle starts then close the door.
(click to enlarge)