Hi James! I discovered what the happened.
The workflow i used didn't work for this project.
What happened was that the Yeti was created in the original mesh. After that animation of the character with facial expressions was created.
I took this mesh and split the head to created the ziva simulations.
After creating the simulations and exporting the Alembic file.
After that, i match the head with the character's body so the Id of the initial Yeti vertices was lost because the original mesh was changed.
I use this workflow to create Ziva simulations, but what would be a better option?