You have changed two major components. By removing the Bear weather rest and shooting off the shelf you have made the bow more center shot, which should have increased your spine need and widened your usable spine range. And shortening the arrow stiffened the spine. If your bow is a Bear recurve it probably has a flat shelf and sight window. Try placing a tooth pick under the bear skin, both on the shelf and strike plate. Place them directly above the lowest part of the grip. See if that changes anything.
Bob