Currently, the documentation page for the HumanoidStateType enum refers to a Standing state;
and also says that Running is said to only be active “while physics of parts in range are being calculated”;
These are both wrong. There is no Standing state, Running effectively acts as that. It is always active when the Humanoid is upright and controllable on the ground, not only when there’s physics stuff going on around the Humanoid.
The documentation should be edited to clarify that Running should be seen as the “I am on the ground and can walk around” state, and the reference to the lost Standing state should be replaced to use Running.