HI Kassandra, As I understand it if humidity is too high during incubation the chick is too wet and can drown during/after pipping.
However, if it is too low during incubation there is not enough fluid around the chick to allow it to easily rotate just prior to hatching, and the inner membrane is applied to the chick. If after pipping this membrane dries out then the chick really can't move and becomes shrink wrapped.
If all your chicks are becoming shrink wrapped then maybe they need a little more humidity during incubation to prevent excessive water evaporation. That may explain why you get so many shrink wrapped chicks.