It may be designed for 620 film not 120, some were It could foul the edge of the pressure plate while the spool is starting but will ease once started. Modern 120 films will just fit into some 620 camera's/rollfilm holders.
I have two Rollex holders and the one that fit's my Etui is fine with 120 film. I can send you a scan of the 1935 BJP - Thorsch & Co advert for the Kamera Workstätten "Patent Etui" if you'd like it.
Which model of camera/lens ?