In my case, the bracket that holds the shell and that of the (OEM) screen were "not quite right."
Not much off in alignment, but enough. A guy like me knows what to do in such cases ... turn the fastener harder.
I did not realize the damage I had done until I decided to get into the shell to connect some (absolutely worthless) led lights attached to my hand guards.
That led to the new shell.
I later sent the POS OEM w/s to Pete who no doubt has some Guzzi Special Tool #324 made for such problems.
I thereafter got the Dart screen -- some of us continue to believe protection has its value, if only to augment our egos.
That was a MUCH better fit, but I noticed that even with it, my main bracket might -- like me -- be a bit off. I was very careful this time around, but you might have Wayne check that bracket for trueness. As does Pete, Wayne probably has tools to measure such things to the micron, not, as do I, to the moron.