Jenn Air Convection Wall Oven lower oven will not stay on

I have an electric Jenn Air double convection wall oven (WW30430). I’ve already replaced the control panel once (after a thunderstorm made it not work at all). I cleaned both ovens, using the clean feature, prior to Thanksgiving and I had difficulty with the lower oven beginning the clean function. I tried numerous times and finally it came on and cleaned. Then when cooking for Thanksgiving, the lower oven would begin with a 100 degree LCD preheat display, then after a few seconds, a code F? (I cannot tell what the number is supposed to be because most of it is missing because it is not lit) appears and beeps. We tried and tried on Thanksgiving and then my fix-it former Navy CB son gave the panel one bang with the heel of his hand and Viola! we were cooking but didn’t dare turn off the oven until we finished for the day. Now the lower oven won’t stay on again. We did the bang thing and it worked again, but I don’t think that is a reliable method for getting it to work.

When doing the clean function, it seemed that the latch on the lower oven wasn’t working correctly because I pushed in the lower door and it worked. That no longer helps the oven to stay on. I’d rather replace a latch or the temp sensor than the entire control panel. Everything works - the clock, the upper oven, the timers for both ovens -(when the lower came on before). Can you help me figure out what is wrong? I don’t want a new oven - I’d rather replace the old parts - newer appliances don’t last due to planned obsolescence engineering.