Sneaky, I know you said your bow is tuned perfectly, however is it tuned perfectly with broadheads? because they act differently than field points.
Just because they are the same weight as your field points does not mean they will shoot the same.
I align my broadheads horizontally, you might try vertical if your seeing it.
I have found if I want perfect broadhead flight, I must tune my bow for broadheads, not field points
Next weekend is the California state broadhead championship, I have been tuning my bow with broadheads the last few weeks and fine tuning it.
I got to defend my championship.
LOL
Please, I'm not bragging, I'm just letting you know, I know what I am speaking of, I hope this helps.