Its all winter project for me. If I see update I take speeduino from car take back home and update. I did not use any other version before. Today was the first start of the car but CLT readings fail. Yesterday I installed speeduino-202012, today started the car. IDK what was the readings before the update
No reason to think there's a problem with that firmware, I'm sure others would have spotted if it didn't read the CLT sensor.
I would guess there is a physical connection problem - the sensor is not connected to the arduino pin.