Dishes not cleaning properly

Hello Technicians, this is a follow up question, from my last question on this Thermador dishwasher.
I have checked all that was suggested from my last question on this product. Drain is clear and unobstructed. Wash arm spray nozzles are clear, detergent dispenser is working properly. Two things I have found ,when upper rack only is used and then you return to both racks the plunger that diverts water to the top rack sticks in the closed position and bottom spray arm does not work , I can take the spray arm off and take my finger and press the plunger down and the spray arm functions properly. I have also noticed the water in the tub is only 110 degrees. The flow through heaters do not come on and heat the water until about 30 minuets into the cycle, according to the service manual the dishwasher will pull 11 amps when The heaters are activated, the dishwasher pulls 1.5 amps for the first 25 to 30 minuets of both normal and heavy wash cycles. Can you advise me on how long into the cycle is normal for the heaters to begin operation and also the best way to stop the plunger from sticking. Any advise is appreciated.