I used https://github.com/20tab/UnrealEnginePython/blob/master/tutorials/FixingMixamoRoot to fix root motion from mixamo. It seems to work fine, I can see the root motion, however when I enable the root motion in animation sequencer and when I enable root motion processing in the preview it seems to be frozen in place.
If I enable root motion on the model w/o root bone it works fine (but it moves incorrectly)