How do I fix this? There was a tutorial on youtube that suggests I need to “reimport” the mesh with an altered transform. The problem is, I can’t reimport what was never imported in the first place. This is because the animation is from the Anim Start Kit on the unreal shop.
You can try to export and edit it in the blender, then re-import it again.
It will solve your problem but it will not work on the slopes or un-flat floor surfaces.
A better approach is to use Foot IK trace, it will calculate your feet position to be always on the floor even on the slopes.