I'm working with a four year old QH gelding. Started him out with a side pull which he seriously didn't like so I switched to a snaffle. Here's the problem: when I put it on him and he's just standing around, he's fine; when I give him direction from the ground and flex him, he's just fine; when I'm on his back, he chews and chomps at the thing (and not in a good way). I've ridden him with it about 5-6 times (10-15 min per session), and he doesn't seem to be getting any better. The question is this: Do I need to try a different bit or just give him more time? If you recommend a different bit, what would you suggest? Thanks!