Pasting Key Frames

I have added a root bone to my character so I can use root motion on some Mixamo animations and when I try and copy and paste the key frames from the x,y,z location of the hip bone to the new root bone it is changing the location from (0.0.0) to something completely different. The hip bone had the locations at frame 1 as (0,0,0).

Any ideas as to what might be going on, Iam new to blender as Iam simply following a blender tutorial on adding root motion to a Mixamo animation for Unreal Engine. It all seems pretty straightforward except its going weird for me.

The tutorial Iam following is this at 8 min 35 secs is where he starts the copy/paste

Any suggestions?

I still can’t figure this out?

Basically I want to paste the keyframes of x,y,z from the bone called Body to the Root bone which has no keyframes, Just prior to this I added a new bone called Root as I want add root motion to the animation hence why I want to copy the keyframes to the root bone.

Below, in the 1st image you can see the keyframes on the bone Body which I copy the x,y,z keyframes.

In second image I select the Root bone which shows no keyframes on x,y,z and the model is positioned at 0,0,0 - all good

In third image I paste the keyframes copied from 1st image to the Root bone and the model flies off into the distance and the animation plays very weird, you can see the copied keyframes on the image for x,y,z

Any ideas ???