The problem is that Mixamo has root as “Hips”, where we have root as “Root” on the ground and Hips matches Pelvis, which is a child of the root.
AFAIK, Mixamo is working on supporting Epic Skeleton soon. What we should do is to re-create Root motion from Pelvis by projecting the motion to the ground. We have that on roadmap but it doesn’t work yet.
I’m working on a animation editing tool aiming for 4.7, when that comes out, you’ll be able to edit that in editor.
Sorry this has been so much problem.
–Lina,