The wind should not really affect the slow panning of the camera, I've never had issues panning at the slowest speeds even in wind.
Mine even does it on the ground sometimes if it isn't mostly flat... it's like the motors don't have enough power to get round the 'uphill' bits unless I turn pan control more than fractionally.
And yet Yuneec had my camera for 4 weeks and said there was nothing wrong with it, noticing neither that problem, or the dimming flashes for which I had originally returned it...