Izzy was also unbalanced and we didn't canter for about 3 weeks. Then we did it in the school and a few times he did feel a bit too close to the floor! But he wasn't really - nowhere near falling over but it felt a bit
He was worse on one rein so we just cantered on his strong rein at first and now we are working on his weaker rein. We are getting there.
I am lucky having 3 lessons a week, I work for myself so can arrange my schedule to fit in with riding lessons! I do tell my clients that I am in meetings though.