Purchased a new Liquid Soap tray and Max Fill Cap. The Max fill cap is supposed to snap into the soap tray and ours no longer did so it floated in the water preventing the siphon action from emptying the cup. The new Liquid Soap tray also has a small hole (1/16") in it to let the excess water slowly drain out.
The water remaining in the tray really isn't a problem unless you spill the water when emptying it.
You just need to empty it to be able to add detergent.