Whirlpool double oven lower oven won't heat since the self clean was used, so far I have replaced the thermostat, temperature sensor and the control board. I tested the heating element and it's good, when I test the leads to the heating element I am only getting 28 volts. I also tested the wires to the oven and I'm getting 120 volts on both hot wires. The top oven works fine but the lower oven does not work in bake, broil or air fry. Am I missing something.