i don' t shoot 3 under but i' m right handed and if i cock my left wrist up ( hand is upward where palm is putting pressure on the handgrip causing torque on the
bow) i shoot left, if i straighten my my wrist i hit " Near" center. if you are shooting a long bow then the grip i discribe does not apply as longbows are designed with balance point over the whole grip and recurves like i shoot are designed to just have pressure at web between thumb and index finger.
other thing would be to continue to push with the left and pull with the right and not relax or settle in. hopefully this will be helpful. - pat