A connection to twitch.map.fastly.net appears to be required to login to Twitch
The tracking filter blocks twitch.map.fastly.net. With this blocked, I cannot log in to Twitch, and it says that my browser is not supported. With this whitelisted, I can log in without any problems. It should be an easy fix to add twitch.map.fastly.net/ to src/exclude.txt.
I am using the Vivaldi version with Qutebrowser’s adblocker, so I do not know if this still persists with e.g. Firefox + uBlock Origin.