Head Light Bracket

The tubes between the triple clamp plates should have a rubber/neoprene grommet , top and bottom. I imagine that if missing, worn or the triple clamps haven't been tightened down enough, these side brackets will move, bit surprised they move that much. Also make sure the bolts either side of the nacel are tight, this will also affect side movement, although they are used for Dip adjustment primarily, but if loose they may affect your headlight in the way you described !
I have had my front end on my 09 America apart to service it and change oils in the legs, putting it back together I had to mount the head lamp then tighten triple clamp / head stem bearings to clamp the side tubes mountings.
Cheers hope that helped.

capt