Just do more..
If you have a clean r-off bhs on the track, then moving to floor is a matter of confidence.
Get a coach to spot you on a few, and make sure you are going through the proper motions.
Think about pushing your feet down and away from you when you jump, and reaching for the ceiling with your hands.
It all works out. Just need to take your time, practice, and keep at it.
If you can, do round-off (stop and feel the position), standing flip-flop, so you begin to feel the transition and body motion.