Vertical position problems when reusing Mixamo animations for multiple models

I am experiencing the following problems when trying to target the same Mixamo animations for multiple 3D models in Unity. I have a couple of animations originally created for, let's call it Model A. I want to assign those two animations to two other models, Model B and Model C. All 3D models were created in Fuse, rigged and animated in Mixamo, and then exported in FBX for Unity format. Let's call the animations Idle and Punch.

In all of the screenshots below Model B is on the left and Model C on the right.

If the settings below (Avatar Definition setting, under Rig, for both animations is set to Create From This Model) are in effect:





the following behavior is observed:

1. During animation Idle, Model B is floating in the air and Model C is on the floor.
2. During animation Punch, Model B is on the floor and Model C's feet are under it.

And when the Avatar Definition is set to Copy From Other Avatar and the source is set to Model B:





the behavior is the following:

1. During Idle animation, Model B is floating in the air and Model C is on the floor, i.e. the same behavior as above.
2. During Punch animation, Model B is on the floor and Model C is on the floor as well.

The Model settings for both animations look like this:


Any ideas what the problem is here? Is it related to all the import warnings?

 

Sorry for the bump. Any ideas why the above problem is happening?