[General] Shandris' Locking head bug

[WarCortez]

There's a cinematic where I instantly move the Shandris model-based hero to a location with some other characters and making her face a unit and lock head on it. However, unlike the other models, her head keeps twitching. Anyone encountered with this issue?

EDIT: I figure it must be related to her stand animation because when I froze her animation, her head wasn't moving. Still not sure what the problem could be though.