
As the natural ear of a briard is a drop ear, the cropping and gluing is used in an effort to stiffen the remaining ear into an upright position, but I would suppose some will never be totally erect. I have seen many Great Danes and other docked docks on programs hailing from USA where the cropped ears are less than fully erect. Some breeds, notably GSD that are meant to have erect ears have them flop too.
I think you will just have to accept his ears the way they are :D Think of it adding character to your pet. Personally I prefer the natural ears.