I just got my hero 9 black and i got the max lens mod and when i go to put it on it grinds and doesnt lock on. Any idea what is wrong? i cannot get it to go that last little bit
Please try to install the Mod again.
Make sure to align the grooves and twist with some force.
It would be a bit tight at first.
You may also check the guide on HERO9 Black - Max Lens Mod
Let us know how it goes.