It could be your hand placement on the grip, A Hill style bow likes to have the grip pressure equally across the palm. if you lift the heel, the bow can react differently. The Howard Hill grip, like little bird that you don't want to injure, but you don't want it to get away either, let the bow sink in and find its spot. Although I find if the bow is settled properly, baring down on the grip,, a bit of white knuckling does not change much, if anything, in the arrow flight. As when shooting a marauding bunny rabbit escaping to the Nederlands. If it is gripped properly the bow will not torque. Total arm rigidity. I use to have a shooting machine, my target bows would blow nocks at twenty yards with the bow vertical, I could then and still can shoot tighter groups by hand than the shooting machine could, shooting with about a 2 o'clock cant. I find that shooting wood arrows that are no longer than they need to be come out of my non-center shot longbows the cleanest. I am always pleased with how nice net arrow length cedars fly out of my duo shooters. Of courses, a broad head cannot be net length, but getting as close as possible helps. My favorite longbows for hunting are 3/8" out from center.left and right. I think the bent bow arm and Hill bird grip allows the bow to get out of the way of the arrow when the release is made. It is simple physics, The string drives at the center of the bow, the resistance to motion creates a bend into the bow with non-center shot bows. That force pushes the bow away from the arrow just a little bit. I have had videos taken of me shooting, that show that bend into the longbow, whether it is a finger release or a center caliper mechanical release. Allowing that action to take place gives a quicker arrow recovery and thus, more consistent accuracy. If in doubt go to the John Schulz videos and do exactly as he says and demonstrates. What he says is every bit, if not more, important than what he shows. Don't change anything and do not add anything.