focus problem at maximum zoom X42 bur good bellow X34

focus problem at maximum zoom X42 bur good bellow X34

Hello I have a small focus problem on my AZ421. when I zoom up to 34 times it's ok but as soon as I reach the maximum zoom 42 times, it no longer locks the lens on a sharp image on 42 time zoom. but it becomes correct if you put your finger at the end of the lens to raise it slightly or if you rotate the camera 180 degrees it can lock the zoom on a sharp image.