One of the standards of the Competition of Energy was not having the capacity to fly. It was even expressed that in the event that anybody attempted it wouldn’t work. Amid the scene, Goku was flying in reverse soon after his change, However it would appear that it was only a hop in the event that you look you can plainly observe it.
It likewise occurred amid Jiren versus Goku battle when Goku assaulted Jiren with Soul Bomb.
Goku looks at in the event that he can fly in the primary scene of the competition, and he can’t. So yes, they really can’t fly in the realm of the void, did you see Goku flying as well?