I haven't used Twitch and my solution is naive but effective so far. I seem to be incapable of making consistent streams using OBS when they are played back with Windows Media Player and the newer Media Player. Invoking one or the other of these MSFT products is vague and support for the original Windows Media Player (which seems to work) is waning. My solution has been to abandon both of them and use VLC Media Player. My echo problems are now gone.