This has been a critical issue with Fuji big rangefinders and for that matter with most horizontal transport medium format cameras. In fact, it's known well enough, even by Fuji that it is addressed in the user guide of many models of Fuji. Short notice to keep film tight on the takeup spool when loading.
Bronica 645rf have been noted to exhibit this same problem. It's a "user" issue most often.
Symptoms of closing the door on loose film are:
1) increasingly hard to advance as mid roll is approached
2) exhibit frame spacing problems
3) jamming at mid roll or later, resulting in having to open the door to strip the film out of the camera, ie no good frames.
Keep tension on both the feed roll and takeup spool with the film advance lever and fingers upon closing the door. A third hand would be nice, but have learned to accomplish closing the door on a tight roll.
Have not had this problem any more on numerous big Fuji rangefinders including the GSW you posted about. Furthermore, I am never hesitant to send any of my Fuji's to Frank Marshman at Camera Wiz for various other problems, including shutter linkages and bellows on the GS645 (3 of them).
I have never had to send one to him for rangefinder, meter or transport issues in over ten years now. If you don't solve your problem with more care on loading, Frank is The Man! He's in Virginia.