Edit Mixamo Animations in Unity

Hello Everyone!

I'm not sure if this is the right place for this, but I'm having an issue I can't seem to find a solution for.

I'm exporting Mixamo animations to Unity, but some have a slightly wonky rotation.

"Not a problem," I thought, I'll just open the animation and edit it!

Unfortunately, no matter what I do, the original animation plays in-game. I've made sure I'm using the edited animation, which works fine in the scene view. 

I'm very confused, any help much appreciated!