Mecanim root motion import appears broken

New to Unity. But I'm moderately sure that this is the tools fucking up and not me. I made myself a model in blender and animated it by creating idle and walk forward sequences. The walk forward works fine in blender and in the preview window of Unity. animation clip

However. When I actually tried using it in the game world with the animators use root motion checked. There was a lot of foot sliding, the amount she was being moved around in the game world by the animation didn't match with the amount she was being moved in the animation. Now, my first thought was that I'd fucked up...that might still be the case but there's a reason I doubt that. And that's this.

I fiddled with the sliders and checked the average velocities. It's only sampling the first few frames of root motion for reasons I cannot fathom.

So the question is, is this a bug? Or am I just not doing it right?