Weather is just good enough to get out to the un heated shop.That's a lot of taper over 4". Have you attempted to level (remove twist) from lathe?
I could get a little head stock movement with the head to bed mounting bolts/wedge/pins. Although it was only in the opposite direction needed.
So its still cutting narrower near the head vs 4” (1” stock) towards the tailstock ( no tail stock support).
Tail stock is definitely off as it gets worse if I cut a piece with tall stock support.
I will get back at it today