Kindly see link below.
After upgrading from 8.5.1 to 8.5.2 Sametime; administrators are unable to save changes to Media Manager to enable new features.
My TURN server is installed together with my media manager and enabled the NATTraversal from false value to true. Check out the two stavconfig file (DMProfile and PNProfile) in the media manager. By the way my deployment is new not upgrade.
Hope this help.