Over the past week, fewer and fewer Chinese users have been able to access Twitch. As of September 20th, Twitch's site and official iOS App were shut down in China, rendering them inaccessible within the nation. While the reason for the ban is unknown, it is not unlike other censorship measures exercised by China.
https://www.notebookcheck.net/Twitch-is-now-banned-in-China.333430.0.html