It sounds like you will have to replace the electronic control. However, we can try to reprogram it. Follow the directions below, selecting 27 from the menu once you get to that part of the programming. Does the behavior change at all?
Within 60 seconds of power up, press the following
OVEN CANCEL, WARM HOLD, BAKE, TEMP DOWN,
TIMER OFF, MINUTE DOWN, MICRO CANCEL, 5, OVEN
START/ENTER, OVEN LIGHT.
2. Size is shown in display - “ID 24”.
3. Press CLOCK pad until correct size is displayed (ID 27).
4. Press CANCEL.
5. Press and hold OVEN CANCEL pad for 5 seconds
to verify programming