Question Timeline interferes with Blendtree

Hi there

I'm running into a problem with my Character-Setup.
My Character has an Animator with two layers: The Base Layer for the Mechanim Animatons and a Face Layer with a Blendtree for the Blendshape with the Face-Animations. The Blendtree Parameter get Controlled from a Script.
So far this works out well. But as soon as I Animate the Character with a Timeline (Mixamo Animations), the Blend Tree Animations seem to bug out. The Blendshape values dont get updated properly. As you see in the Screenshot all the Blendtree Parameters are set to 0, but the values on the Blendshapes are all over the place and get stuck at random values.


Does somebody have an idea what is going on here, an how i can get around this issue?

Thanks!


(Unity 2019.4.8f1, HDRP, Timeline 1.2.15)