made the mistake of teaching a young horse flying changes too early, she could do fabulous 3 time changes but I could never get a counter canter and it was a struggle sometimes on the diagonal because as soon as my weight shifted she'd change. This made getting her out of the lower dressage levels quite difficult.
Yes frog, I did practically the same thing, I was so stoked that I taught a young horse to do a nice balanced flying change, and then when I was teaching other movements, as soon as I shifted my weight, he would change. And it became very fustrating...
To blossum...Seek professional help darl..