Hopping during Flying Lead Change

So I have started my horse on flying lead changes. Things were going great but lately she has started hopping in her hindend and changing behind first then changing in front.

I think that I might need to go back to the basics a little and just work on swinging her shoulders and getting her really lifted back up. Any other advice on how to get her to stop doing this and keep her from doing it again in the future?

I'm really new to the whole flying lead change thing. No one else at my barn can do them, just my trainer, and only on a few of her horses. So I've mostly just been going off instinct and watching other people do them at our shows.

Here is a small video from just last week.
We start changing leads at the 5 min mark roughly. Sorry I don't have more examples. If you want to suffer through my pleasure practice, go right ahead, and if you have any tips on how to get her to extend her front leading leg when on the right lead, that would be nice too, but it's a side thought.

Ok so I am absolutely no expert on flying lead changes so if I'm wrong please forgive me.
One thing my trainer told me is that flying lead changes are easier for the horse at a faster pace. Now I realize that you do western pleasure so you might not want to speed up your horse but it really worked for me. When my 3 yr old was learning flying lead changes she was always pretty relaxed going into it but running going out. Now she is relaxed all the way around (just learnt them this spring). Another thing I found is while she was at that point when she was relaxed going in but tense coming out was that I was trying to control her too much. I had her so upset that she actually lost her flying changes for about 2 weeks. Then one ride I was just fooling around and lopeing her in her circles (by the way we compete in reining) and had my reins so loose that if she would have done something I would have been in trouble. Anyway point is that as I was loping completely with just leg cues I randomly tried a lead change and it was nothing short of perfection. Now lead changes are awesome. She loves it and so do I.

Sorry for the novel and my life story :P Hope I was slightly helpful.

I copied/pasted my answer from HGS :)
Just to put it here, too, since there may be different people looking....

A correct lead change is from back to front. It is hard to tell from your video... your horse only hops for one of the changes. It really looks to me like he is just trying to do a correct lead change, but it's harder since he is going so slow. Can you get a video of you riding more forward? A nice working trot, canter, and lead changes?

I really feel like he is just putting a little "oomph" in there for the change. Has he been evaluated for soreness and saddle fit? Another thing could be that he is slightly protesting the use of the spur... but I don't know, since you are using them other times without a fuss.

As Imagine said, lead changes are from back to front. A horse has to rock back on their hind end so that they can move their front legs. He seems to sort of be falling on his forehand as you go along, and he has to hop up onto his hind so he can properly change without falling. You should probably work on getting him off his forehand a little, especially for lead changes.

Correct me if I'm wrong.