If you can't connect to the Teamspeak server using ts3server://321dive , try these methods.
Update your client.
Tested Client Versions - TeamSpeak 6 Beta, TeamSpeak 5 and TeamSpeak 3.6.2 +
Old versions from http://ftp.4players.de/pub/hosted/ts3/releases (EOL)
We recommend you to use "ts3server://321dive" or "ts3server://blackwatch" instead of the IP or Domain name.
-RILEY
We hope that you have a good day !!