I did buy and replace the water level switch AP4568364 which did not change the water level beyond 1/2 full. I saw the technician adjust my old switch which brought the level up a little bit more.However your not answering the question of how much water should be in the tub for the rinse cycle. The water level does not cover the clothes during the rinse cycle. The control panel switch is on full load, or whatever it says, I am not at the machine for the exact wordage.
Answer Gene, Since you've replaced the "low" water level switch, already, did you also check the air dome hose(tube) and "T" fitting for clogs, kinks and debris ? and is the washer draining, completely, between the wash and rinse cycle ? If that's all OK, then replace the water temperature control board 8578168 When the "add softner" is selected, the tub should fill to the highest setting, When left deselected, the water level will only fill approximately 1/2 full. Thanks and Good Luck