Reply from https://mobile.twitter.com/eastdakota/status/991718955021623...

@DnsLearningOrg Replying to @eastdakota and @ATTCares

This may be our fault. DnsLearning.org / StudyCity.org has implemented DNS servers with two modes. Study mode and Play mode. After 1 hour, "YourTube" and other play sites are blocked. 1/2

All you need to do is link your Khan Academy, DuoLingo or Mathopolis account with us and do 5 problems. DnsLearning / StudyCity.org will automatically detect when you earn points and switch your data center back to play mode. 2/2