The difference could just be due to a difference in adjustment of your fascia.

Nah... I thought about that first. No amount of fascia adjustment is going to do it. This isn't like a tiny gap. To give an idea, I can fit a credit card in the gap very easily, two credit cards on top of each other fit in a little more snugly. I'm not sure what that amounts to in terms of measurement, but it's nothing that a fascia adjustment can take care of, unfortunately.