Sounds like it's working as designed, on loading you wind it with crank on the back to frame 1 where it will stop (assuming it's an "Automatic" back). If you trip the shutter then use the crank on the back it will let you wind off the rest of the roll. Once you've loaded the film, just use the camera's knob/crank, unless you want to finish off the roll early.
You can download the camera's manual from www.hasselbladhistorical.eu