I had a lesson with Chemaine Hurtado, owner and trainer at Symphony Dressage Stables, a week or so ago. Before she got to the ranch, I warmed Speedy up with some walk and trot. I had given him three days off after a bareback with a halter ride, so his attitude was much improved.
When she felt that he could give her the new bend, soften, and relax, she asked for the flying changing, and got it. I got on him and worked through the same thing. Instead of asking for the change, I only asked for the bend. She made it look easy of course, but going back a step to improve the counter canter really worked.
My new plan is to focus on getting a softer change of bend wherever I want in the arena. And when I feel that Speedy is soft on the inside rein, that's when I can ask for the flying change.