This is one of many errors I receive when attempting to play mobile, in browser or app. I'll get a few placements in before it just stops loading and inevitable has something like this pop up. Then the reload takes 5min or more.
A workaround is to load incognito and login to SR which works for a bit. But I can only login so many times before twitch thinks something is up with my account. This shouldn't be the case and it shouldn't be a struggle to play on mobile.
The one featured is when trying to claim a chest.