As always, hard to tell without a picture or video but I'll take a guess -- and it is ONLY that, a guess!
Many times with locator and pistol grip style bows, the shooter does not allow the pressure point of the bow grip to press into the end of the ulna of the forearm. All the pressure into the hand is in the web of the hand and that is in the deepest point of the grip. this location is usually an inch or two ABOVE the pressure point.
So, the bow, being supported above the pressure point, will rotate upper limb forward and lower limb back (into the leg as you stated).
Try allowing the bow to press lower on the pad of the thumb (hypo-thenar eminence) and not so much in the web of the thumb and index finger.
See if that helps.
Arne