Thermador Hood PH48ZS, buttons for fan not working

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Brand:Thermador hood
Model Number:PH48ZS
Main Symptom: buttons to activate the fan are not working
What happens & when: just happened but buttons have been needing repeated pushing to activate fans and also repeated pushing on the off button to turn off fan, The buttons for the lights and the heat lamps are working just fine.

Error Code (if any):
Parts or tests already tried:
Photos / video link:

It sounds like the control buttons are starting to go out. 00427159 Control Unit | Genuine Bosch OEM In Stock