Sounds like the game is still trying to join that channel on login.
No idea if it would work, but I noticed that when I copied my character settings from my main account to my other account, logging in on the other account tried to connect to chat channels my main was using. So perhaps you could use that intentionally?
Copy your UI settings from another character to your main, see if it helps.
(Copying involves copy pasting and renaming some files in a certain folder, I don’t have the bookmark here but google-fu can hopefully find the instructions)