Twitch streams at 1080p jerky. I do not know why. There's nobody on the internet (50k line) or nothing else should interfere with the Wi-Fi. So what could it be about then?
If it should be important: Chromecast 2nd generation
This can have many causes, e.g. The fact that the Twitch servers are busy and only allow a limited bandwidth at your location can come from your Internet provider, who may promise you more speed than it delivers or the strength of the Wi-Fi at the location from the Chromestick, etc.
But that has been since we had the new Internet (2 months) - the full bandwidth is available. And the Wi-Fi shouldn't disturb anything. I'm also right above the router