Animation retargeting is done using unreal tools (https://docs.unrealengine.com/latest/INT/Engine/Animation/RetargetingDifferentSkeletons/index.html).
The PROBLEM is that original animation has root motion, new retargeted version doesn’t have any root motion in it.
So, there’s no issue with mixamo animation. The problem is with retargeting process (root motion information is lost). And I’d like to know how to deal with this.