Great asset (but I have an issue)!
When I use the provided fbx assets in Mixamo, everything works perfectly. However, I modified the assets in Blender 3.6 and exported as fbx, and they no longer worked in Mixamo. I was curious, so I tried opening the unmodified blend files and exporting as fbx. That also didn't work in Mixamo, so I don't think my modifications are the issue. Was looking for some advice on what to do.