It is probably a silly question but if you look at the wind speed sensing propeller, does it’s speed seem to fluctuate in synchrony with the reading provided, i.e. start slow, pick up and then fluctuate? If it does then it is likely to be a mechanical problem, if not then it is down to the electronics / wiring.
I would still re-make the connections to the server.
The membership association for owners of Dufour Yachts