I've been using a GW690 for the last year or so. Fuji, Kodak, Ilford films. I've had a couple of loosely wound rolls that showed light leaks. These were from sloppy loading and unloading in the field, nothing else. Keeping tension on the roll when starting, keeping the wind lever tensioned until the back is closed, and each brand has worked fine for me.

Not sure why the switch from one brand to another would be the action that caused loose rolling for you. It's not like there is a film thickness sensor or such in these models.