Hey,
I am did an Animation Re-target with the Animation pack blueprint made by Unreal in the marketplace. When I set it up for my Skeletal Mesh, my character looks like they are floating when they walk and the death animation occurs midair. I have setup the bone retargeting information for Animation Scaled like suggested in the unreal tutorial but I am still getting this issue.
First thing you can do is to check the physics asset to see if the capsules/boxes for the bodies are lined up with the feet.
Next if that doesn’t fix it you can export the animations and import them again with a minus translation in the z (or whatever the up axis is) to line the animations up with the ground. You can start with one and when you’ve found a number that looks good just use that for all of them.