The ogive isn't an exact point on the bullet , its the curved area between the bearing surface of the bullet and meplat (tip) .,
Mountainstalker is suggesting that the polymer tip is perhaps making contact inside the seating stem before actually making firm contact with the ogive , causing variations in seating as the tip deforms . As this is a new problem , I would still suspect neck tension .
My suggestion would be , measure a load of bullets (to ogive) and group them . When you've 6 the same , remeasure them , to ensure its not your technique , which I'm not doubting . Ensure you've properly chamfered the case mouths , then seat that group and measure . Now inspect them closely for any marks or damage to the bullet or polymer tip . Pobably easiest to do by photographing and expanding the picture .
If after this the variations using the matched group are still present , I would be fairly confident in saying its time to anneal . If you're not confident and don't want to commit a full batch of cases to annealing , why not ask on the forum if an SD member would do half a dozen for you ? Otherwise, you're going to be chasing your tail in endless circles .
Good luck ,
FT