"StateMachineBehaviour" Not working for sub sates ?

"OnStateMachineEnter / Exit" not working for sub states as mentioned in the docs it is very good for sub state not to trigger anything if transitioned between states in a sub state however OnStateEnter / Exit is triggering on every enter and exit for states in the sub state "however i didn't put any behavior scripts on the states just one on the main sub state" i'm really confused there is 2 used info one in the comments in the behavior script and one in the docs Any help is appreciated