Question How to correct root motion from an animation job?

I'm trying to do some root motion correction in AnimationScriptPlayable.
In my test code, the expected output is (0.00, 90.00, 0.00), but the actual output has a big fluctuation range, even negative values.
Is there any way to fix this problem?

Test Code:

Code (CSharp):

1. public struct RotateJob : IAnimationJob
2. {
3.     public static readonly Vector3 rotSpeed = new Vector3(0, 90, 0);
4.  
5.     public void ProcessRootMotion(AnimationStream stream)
6.     {
7.         var angular = rotSpeed * stream.deltaTime;
8.         stream.angularVelocity += angular;
9.     }
10.  
11.     public void ProcessAnimation(AnimationStream stream)
12.     {
13.     }
14. }
15.  
16. [RequireComponent(typeof(Animator))]
17. public class Test : MonoBehaviour
18. {
19.     private Animator _animator;
20.     private PlayableGraph _graph;
21.  
22.     private void OnEnable()
23.     {
24.         _animator = GetComponent<Animator>();
25.         _graph = PlayableGraph.Create();
26.  
27.         // clip playable
28.         var animClipPlayable = AnimationClipPlayable.Create(_graph, null);
29.  
30.         // script playable
31.         var job = new RotateJob();
32.         var animScriptPlayable = AnimationScriptPlayable.Create(_graph, job);
33.         animScriptPlayable.AddInput(animClipPlayable, 0, 1f);
34.  
35.         // output
36.         var animPlayableOutput = AnimationPlayableOutput.Create(_graph, "Test", _animator);
37.         animPlayableOutput.SetSourcePlayable(animScriptPlayable);
38.  
39.         _graph.Play();
40.     }
41.  
42.     private Vector3 _lastRot;
43.  
44.     private void LateUpdate()
45.     {
46.         var currRot = transform.rotation.eulerAngles;
47.         var deltaRot = currRot - _lastRot;
48.         var rotSpeed = deltaRot / Time.deltaTime;
49.         _lastRot = currRot;
50.  
51.         Debug.Log($"RotSpeed: {rotSpeed}"); // not equal to RotateJob.rotSpeed
52.     }
53.  
54.     private void OnDisable()
55.     {
56.         _graph.Destroy();
57.     }
58. }

Output: