The soap dispenser lid does not open to release the soap powder. I have to manually release the lid at the appropriate time in the cycle by opening the door of the dishwasher and snapping the lid open.
I had the exact same problem with my Maytag dishwasher and Gene the Senior Tech told me to replace the wax motor for the dispenser and it now works like a charm. The part number you need is AP4110779. Click on your model number in your post and look at the drawing for the soap dispenser.
Mike