are you setting the channels to permanent via the teamspeak client?, they are NOT permanent by default. ive just done a quick test and can successfully create a new channel, mark as perm, and restart the container, reconnect and see the channel i created.
Yeah the channels are permanent.
I have to re-enter the private key every time I restart/update things to reclaim server admin. Not sure what I'm doing wrong because your sonarr, sab, plex and couchpotato docker clients are all working perfectly.