I’d say go to incognito/private browsing to clear cookies, go to the xfinity website and login to your INTERNET ONLY account, then click this link and select “turn off” where it says auto authentication for third party apps. Then ESPN and Roku will let you actually login to your family’s account instead of automatically logging you in to your …
https://www.reddit.com/r/ESPN/comments/q1uwff/espn_auto_login_to_xfinity/

