'humanoid'
that is the Mecanim bone retargeting mode.
That means it converted the bones in your mesh to a Unity humanoid Bones setup
in this mode can exchange the animation different avatars with each other,
In these mode the head bone are limited (look in the head tab, you will see only jaw and eye bone
but for the proper play the bone facial rig animation lacks the other facial bones. Therefore I suggested use legacy mode , but if you like the animator state machine then is generic your choise.
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liebe Grüße vidi