I'm trying to add draft to an inner wall of the part and I'm having some trouble. I'm using the draft feature, but I'm not sure why creo doesn't want to create a draft in this location.
Kinda looks like a bug to me. I think I was able to reproduce what you are showing... As a work around, I switched the Draft Hinge and Pull Direction to the opposite side of the part/or a datum plane and everything worked fine. Could also be related to model accuracy but that seems weird since simply choosing a different draft hinge/pull directions works. You could contact PTC support to have them look at it.