I use both linux (Ubuntu 18.04) & windows 10. I am not a streamer, but I did a lot of testing with twitch integration. You don't need to stream, but if you are logged into twitch before hand, it will help speed up the process. I have never been live personally, other than as an extra on stream, or in discord.
I did most of my twitch integration offline. There's two main conflicts I can see happening, one is something that can be easily addressed, the latter not so much. If you login to twitch before your session, the authentication should just be a button click, without needing to login. There is a timeout on the login. If you take too long to login, it will fail.
There's something else that we noticed. Sometimes twitch can get finicky. You could login one day with no fails at all, and then the next day have to re attempt 3 or 4 times.
There might be something else happening with your network.