I checked that Animator.gravityWeight = 0;
How do I make that 1? Does that have to be done inside the 3D modelling software or can it be changed through script or import settings?
The Animator.gravityWeight is driven by Bake Into Pose position Y. When enabled, gravityWeight = 1, when disabled = 0. gravityWeight is blended for clips when transitioning between states.
Animator > Update Method = Animate Physics
Animator > Culling Mode = Cull Update Transforms
with true code and these settings, gravity working well after the animation.