Neck Differences on Axis

I have an Axis that seems the action goes from consistent between the low e and high e side and gradually the high e side action gets higher than the other side, its abount .5mm higher around the 17th fret. The high e side is actually lower at the nut than the other side. It would have to be the neck and not the pocket, bridge, shimming etc since its not consistent throughout the whole neck. I cannot see any twist in it. My other one is not like that. I measured from the body to the fretboard both sides and its about .5mm difference in the neck height and its secured to the body well. Can that just be due to the hand sanding, wondering if some others have necks like that from differences in sanding possibly? I am assuming that’s the difference but wondering if there’s a slight twist there that I am unable to see.