How are the leaps on floor, it is a fear thing that the leap on beam is not getting better. Have you done leaps up to blocks or mats on the floor, we also do them starting on one knee and do leg swings up to the panel mat. I'm not sure if you are doing leg drives from your knee, we start doing these first just to a releve, then to hop landing on one leg, making sure the free leg remains horizontal. Once they have this down we go to swing to assemble. It is very important that once they move to the assemble they get the free leg to horizontal before bringing feet together. Then you can add the back kick after the assemble. Then start doing leaps from the knee.
Hopefully you can make sense to these!