Arducam 6mm lens camera not working?

I’m using the " Arducam Lens for Raspberry Pi HQ Camera, Wide Angle CS-Mount Lens, 6mm Focal Length with Manual Focus and Adjustable Aperture" ( But when I try to rotate the back lens labelled near/far I cannot get it to move. I have tried unscrewing and moving the lens or loosen the screw as well and then move the lense and have looked at videos of people using but for them that near/far lens work. Am I doing something wrong? I’m very unfamiliar with lenses so thank you for the help!

Have you ever referred to the link before?