Hellow Clowenthal, I’ve done testing on my unit which is on the same version as yours, and the unit does work. Are you doing testing with a manual operation or through a programmed run? The manual watering will override the rain sensor, so that is not a working way of testing the sensor. I would program a custom watering for a few minutes ahead of the current time. When the system kicks on, hold down on the sensor switch and that should shut the watering off.