Sprinting and toggling your weapons alt-fire will cause the player to stutter step. This stutter seems like an attempt to complete the alt-fire but is cancelled since the player is running. Player will continue to run if sprint is held. Alt-fire will not activate/complete.
Alt-fire can only be done if walking or standing still. Please update this to allow sprinting actions, such as turning on your flashlight. (or reloading your gun!)