First step when working with rigify is to create a meta rig, a minimal rig with propor hierarchy.
Once you have the meta rig aligned, you generate a rig, which very different hierarchy and much more control bones.
The animation is done on the rig, so the bones that are key framed belong to the rig and not the clean meta rig.
When exporting the animation to UE (only deform bones) the bone hierarchy looks like this:
Which creates issues in UE.
I need the animation that was created with the rigify rig, to be exported with clean skeleton of the
Trying to load an action that was created with rig to the meta rig is loosing some of the movement for reasons that are not clear.