Unknown distance should not affect left to right, only up and down.

I suspect the unknown distance affected your form, like you did not follow through because you wanted to see how it flew. Just a guess.

If you can shoot known distances, you can also shoot unknown distances. Remember, you should select an aiming point on a deer that allows for some miss judgement of the yardage, that still getsa vital hit. If you think a deer may be at 25-30 yds, put your 30 yd pin on the heart and release.