Hand skeleton data startboneId issue

Hi, I'm trying to get hand skeleton position data from quest3.

I'm following https://developer.oculus.com/documentation/unity/unity-handtracking/ and https://www.youtube.com/watch?v=DR60_TCkmAY&t=305s this video.

But when I return handSkeleton.GetCurrentStartBoneId(), even though I added the hand skeleton(OVRHandPrefab) into the script explicitly, it gives me start bone id is FullBody_start.

The thing weird is end bone id is Hand_End properly.

Is there anyone else who struggled same problem with me?

Any suggestion or solution?