Question Destroy AnimatorControllerPlayable and keepAnimatorControllerStateOnDisable==true, default pose miss

I created a PlayableGraph with an AnimatorControllerPlayable which runtimeAnimatorController is the same as animator's runtimeAnimatorController. when animator.keepAnimatorControllerStateOnDisable is true, and I destroy the instance of AnimatorControllerPlayable, I found that the rotation of the charactor's root was error and unpredictable. I seems to be missing default pose.
When I set keepAnimatorControllerStateOnDisable = false before destroying the instance of AnimatorControllerPlayable, and set keepAnimatorControllerStateOnDisable = true next frame, it seem that the problem is fiexed. But why will that happen? Can anyone teach me? Thanks.

Code (CSharp):

1. m_graph = PlayableGraph.Create(m_animator.gameObject.name + "_fade_" + m_animator.GetHashCode());
2. m_graph.SetTimeUpdateMode(DirectorUpdateMode.GameTime);
3. m_fadeOutput = AnimationPlayableOutput.Create(m_graph, "fade", m_animator);
4. m_fadePlayable = AnimatorControllerPlayable.Create(m_graph, m_animator.runtimeAnimatorController);
5. m_fadeOutput.SetSourcePlayable(m_fadePlayable, 0);
6. m_graph.Play();
7. m_fadeOutput.SetWeight(1f);
8.  
9. m_animator.keepAnimatorControllerStateOnDisable = true;
10. m_fadePlayable.Destroy();  // character’s root node's rotation is error after m_fadePlayable.Destroy()