Can you give us some more information?

Is the animation being applied from an animated pose, or a BVH?

What method did you use to construct the animation, and in particular how did you implement the yTranslations of the figure, in the hip, or BODY?

When you created the animation, if the BODY had  none zero yTranslations in any frames, or any none zero x or z rotations, that could be the cause of your problem. Usually when you create an animation, the translations and rotations of the BODY actor should be zero throughout. This does not really matter that much if you are only saving as pz3, but when saving as a pose or BVH it does matter.