I have difficulty acquiring rapid focus on my 600 pf and 400/4.5 lenses. These lenses do not readily find focus on closer subjects when the lens is focused on infinity. But are quick to focus if the lens is focused at a close distance at startup. I have tried and failed to setup a button on the lens to rack the focus back to the closest focus of the lens. I have essentially given up trying to set the “recall focus” button on the lens and am currently racking the focus back by twisting the focus ring. I’d appreciate any guidance offed on this issue. I shoot with a Z8 and Z9.