I understand your concern with protecting your teenager and restricting unwanted content from displaying on their phone! I would be happy to assist.
This could be a result of a few factors. What model device is the teen using? Was the content filter working at any point; did this just start happening? Most of the troubleshooting would be on the account level, so after determining the feature is setup correctly and the device is functioning properly I would like to do a little more account investigation.
Please reply to my direct message with the requested information if your teen is still experiencing the same issue.