It is the non-normlaized gltf root node: https://playground.babylonjs.com/#JUKXQD#5965
Baking will not work for rigged meshes though (afaik). I got it working by ensuring that, in Blender, the armature is normalized. Havok was fine with it then.
Can you double check? The model might be flipped now on x (I think). You need an asymmetrical model to check!