I screwed up on my first post. Sorry.

When you say as you step back you mean that you are still using the 20 yd pin but moving back to 25,30,35 etc?

If so, sounds like you need to move your rest right.

Have you tried centering the rest with the riser and cams/wheels? Easton has a good guide on how to do this and it helps for a starting point. Start there and then adjust as needed.

Move in the oppositedirection of your miss with your rest. Move the restright and it will make your arrow move to the right. Adjust a very small amount (1/32") and shoot again using step back method that it seems you are using now.

Chase the miss with your sight. move in the opposite direction for tuning your rest.