Bouncing at the canter?
So i've just recently gotten back into riding within the last several months, after putting my horse down last year, and i've been having trouble staying still at the canter. I never had a problem on my old horse, he had pretty smooth movement(he was a quarter horse). I ride English, in a general all-purpose saddle, no changes in that from last year.
The horse i'm taking lessons on is an arabian, he's a little taller and leggier than my old horse, and his gaits are just so much bigger and more elevated. When I ask for a canter I tend to bounce and feel myself wanting to go into a half seat just to stay still. I thought the problem would disappear after building back some of the muscle i'd lost, and it has lessened but i'm still bouncy.
When I ask for the canter from a walk or a halt, I usually get a much more collected response and it takes less time for me to stay still, but especially asking from a posting trot, I end up going for quite a few strides before I can collect enough to have a quiet seat.
Does anyone have any advice to either build up more muscle to allow me to control my body more, a different way of sitting, or any sort of tip?