[jsmith948]

We haven't seen any movement such as you describe when we hitch or un-hitch our 5er. I would check for bulges or buckled, out-of-alignment panels in both the interior and exterior of your bedroom. How much does it flex? Can you feel it while towing? You might do a forum search for threads regarding frame issues.
What you are describing could be an indication of a weakened or cracking frame.