Or more likely, what I found is that the ear covering bits are extended too far and the plastic bit is struck by the stock as you mount the gun. If you adjust the ear defenders for as small a head as still covers your ears, then the annoying whacking-stock-on-ear-defenders is reduced a lot.Ttocs, if your ear protection is interfering with you mounting your gun, you are doing it wrong. I suspect you might be one of those people that tilts their head over towards the top of the stock to look down the gun. Try keeping your head vertical. Your bedroom mirror can be your friend here.
But whatever you do, persist until you find a method that works for you.