Have you read:
http://support.nabble.com/HELP-NEEDED-nabble-forum-currently-is-not-mobile-device-friendly-td7595312.htmlIn your case it sounds as if it is the site in which you are embedding your forum that may be causing the problem. It might be worth posting to URL so it can be checked out.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.