Why does my Blender animation look buggy after importing to Unity?

I’ve created some animations in Blender. Two work fine, and one looks bizarre. I went through the same export/import process for each.

Here’s what the wonky animation (a swipe attack) looks like in Blender vs Unity.

Can anyone help me understand what’s going wrong? No one responded to my last post, so hoping someone can guide me in the right direction. Thanks in advance.