It was already discussed, and it's not really a problem of the scenery, but rather an annoying FSX bug, that a small object needs to be "awaken" to respond to simulation variables, then it stays active. If you go close to the windsock, it will fix itself, and will stay that way.
We would like to find a way to fix it, without reverting to the ugly default windsock, but we haven't find a satisfactory method yet, the scenery will surely be updated when we'll eventually find a solution.
