Don’t scoop the board like a fakie front shuv. I think taht May be your problem. The board should stay stuck to your feet the whole rotation. Just set up in the foot position, pop, wind up your shoulder, slide, turn, land. Make sure your shoulders turn first while your hips follow. P.S. by wind up I mean when your poping wind your shoulder up to do the turn.

Use your feet as a guider and it should basically stick to your feet if you position it right

It is also possible that your griptape ist just too used. Maybe buying a new one will help✌️

Try doing a fakie revert to get used to the feeling of turning

When the board gets 90 degrees into its turn dip your front foot downwards it helps to keep your feet on the board

Keep your feet a little closer together from the beginning and u should be good it should happen less often