EA1EF, I'm not clear on what you are trying to say. Is there a known issue with newer Davis anemometers physically getting stuck at low wind speeds? I have not read this on this forum, but maybe I didn't go back far enough.
I have had that situation happen one time, with a new Davis unit bought six months ago. The wind speed graph on the station's webpage stayed absolutely on 0 for over 12 hours. When I went to inspect the station, I could gently rotate the cups backward and let them go, and they would stop abruptly at the same place, again and again. (I could verify by the location of the set screw.) Rotation was smooth and easy, but it just stopped when it reached that point.
I finally gave the cups a good spin in each direction, and then they went back to their normal slow speed rotation, without stopping at that spot.
Rich K.