When the ring goes up and down, it usually means that someone pulled the mat up, bending the metal. Fastening the mat back to the platter does not always straighten out the ring. The factory glue between mat to platter is contact cement. The ring has a different type of glue. Good luck. You may want to consider making a new mat [do a search here to see what you can make]. If you make one that looks nice, it can replace the old one.