Enum.MouseBehavior.LockCenter Doesn't work unless looped?

Using The Sample Code Below from my script Doesn't seem to work unless my mouse is clicked inside of the game window beforehand. It works fine if I loop it, but then i'm not able to toggle it back to it's default mouse behavior so I can access guis.

wait(1)
camera.CameraType = Enum.CameraType.Scriptable
main.uis.MouseIconEnabled = false
main.uis.MouseBehavior = Enum.MouseBehavior.LockCenter