Do you mean the rubber grip is rotating on the bar? If so it's probably not been installed with any / enough grip glue, or they've not used the proper stuff, some cheap brands can soften up when the heat is turned on. If I were you I'd get the supplying dealer to sort it out. As you know they are a big heavy bike, you dont want that grip rotating if you are trying to push the bike around whilst you're off the bike.
As for the brake light mine has the same play in it.