I have the same oven & same problem: the oven appears to work perfectly, as does the display for all oven functions, timer and even to set the clock... but the clock will not display after setting the time.
This happened after a quick power outage. I tried cycling power, leaving it off for a minute first. Same symptom.
I had replaced the control board and keyboard two years ago after getting the error code. This time no codes, just no clock.
I was hoping there may be some sort of power-savings mode, or some "feature" to disable the clock for people that don't like the fluorescent display lighting up the kitchen at night. Hard to image there could be a hardware failure that kills the clock but allows all other displays and oven functions.