Looked at the spacing on the beak? You said it had been down and maybe tweaked.
I had taken the beak off to install a oil cooler guard and apparently didn't get it quite right when I re installed it.,
Close, but not quite right even though everything looked OK and I got the same sort of sound. This was especially true when it was cold and I first started out for the day.
Pulled the beak back off and put it back on and the sound was gone.
Mine is a 2011 so not sure if my experience applies here so take it with a grain of salt. And maybe some Tequila...