Using basic vector math, assuming on a broad reach the angle of the wind is 45 degrees aft of the beam, than any windspeed over 11.31 knots will feel like it's blowing from aft to forward; the faster the windspeed, the higher the forward component of the wind.
You are failing to factor in the forward motion of the boat, ie... appearent wind speed. As the true wind speed picks up so will the boats speed, to a point.
hunter Legend 37 Semper Paratus
Formerly - Tartan 34C Yawl