The rings on my Copernicus are tight, i.e. they cannot be turned around.
But I guess it would be a good idea to contact the Montblanc customer service (may be even call them here in Germany).
First, because they might (or not) be able to fix it. Unfortunately, its sometimes not possible to fix Patron of Arts pens!
Second, the MB customer service can give you a "official" assessment whether the loose rings represent a defect or not. At least from my perspective, the rings should be tight ...
Kind regards
Michael