I tried to strap down the loose side with the provided straps but it didn't seem to do much. I ordered some longer ones from Amazon and I'll see if it makes a difference.
I have this EXACT same problem. I sent a video to my dealer and said I'd like it looked at next time I bring it in. I'm not sure I want to wait that long, however.
EDIT: Here's a video of the issue. It may not seem bad from this, but when you're driving it's "clanks" like that non-stop.