Board Thread:General Discussion/@comment-35455126-20190312165214/@comment-1292715-20190322225129

They need all four CCT Towers running to maintain global communication. When Beacon's Tower was destroyed, it caused global communication to shut down entirely. And since Altas was the one who brought the CCT technology to the four kingdoms, and they closed their borders, plus the Grimm infesting Beacon, there hasn't been an opportunity to fix it.

So while local communication is still possible, global communication across all kingdoms are currently impossible.