There seems to be an issue with chat embeds, where it’s not able to log in the user for chat properly.
The direct url works just fine, as well as the popout chat. No login prompt is displayed for that.
It navigates to the Twitch login, but once logged in (or when you’re already logged in) it keeps displaying this screen:
The login window navigates directly to Twitch’s front page after login/redirect, and nothing happens after that.
Tested with Safari on iOS.