Horse's Jaw is Locking on Downward Transition from the Canter
Hi! I recently started leasing a feisty pony who has come a long way already. A small problem I am trying to tackle right now is her downward transitions. I know that getting a good transition takes time and lots of practice, but I am concerned with her habit of locking her jaw. She mostly does it from canter to trot and mostly going to the left. When I ask her to come down, with verbal cues, seat, and light half halts she instantly locks her jaw on the left side, shoves her neck to the right and comes off the rail. If I try to put her into a circle of any size to get her to stop and hold some sort of bend, she just won't stop or will force herself out of the circle. I don't want to use force and I don't think it would work with her anyways. Lately I have been asking for the transition on a completely loose rein to show her that I won't grab at it and she doesn't need to brace against me, but that doesn't seem to help much. Any ideas on helping her break this habit? She flexes well in circles at the walk, trot, and canter, as well as on the ground. It's just at the transition.