I have noticed is zipping noise when advancing film on the Pro-S back for the Mamiya RB 67. I don't remember it making this noise on my first roll. Is this normal for it to sound like that? From what I would guess it's only supposed to make the sound of film and paper sliding smoothly to the next exposure. Not sounding like a disposable camera or holga with the godawful zipping sound. It also feels like there is excess drag or tension when advancing frames. Here is a video clip of the zipping noise in action with audio. Any advice on what might have caused this issue and possible solution is appreciated.