Works for me. It could be that you're in a cutscene that won't end because the Player can't reach their destination.
But you shouldn't set it to zero, as it will stop your Player from being able to change direction and - depending on your settings - will prevent him from reaching his destination when moving, causing them to move forever in the wrong direction.
If you're making a 2D game, the "proper" way to make a character uni-directional is to either uncheck "Multiple directions" in their Inspector, or rely on Sprites Unity Complex animation, so that you have complete control over which directions he can and can't face.
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But you shouldn't set it to zero, as it will stop your Player from being able to change direction and - depending on your settings - will prevent him from reaching his destination when moving, causing them to move forever in the wrong direction.
If you're making a 2D game, the "proper" way to make a character uni-directional is to either uncheck "Multiple directions" in their Inspector, or rely on Sprites Unity Complex animation, so that you have complete control over which directions he can and can't face.