I seem to have the same issue. It appears that the screen box at the top that it rolls into is not parallel with the floor. It unrolls and the magnetic catch on one side grabs first and then the other which twists the screen enough to cause a loss of tension and the breeze allows it to flap. My guess for a fix would be to re-set the top roller parallel to the floor so both catches touch at the same time or possibly raise one catch to maintain that needed tension.
2006 Ram Mega Cab
2011 Octane T26Y