LookAt for Vistual Bone not work

I’m doing an animation for the eyes of a MetaHuman character (look in the direction) according to this video: https://youtu.be/NZmQPSKf7YY

But LookAt does not want to work for a virtual bone.
If I change the bone to any built-in, then everything works.

Unreal Engine 5.1

Is this a bug or a feature?
How to solve this?