I have the same issue right now, extremely frustrating. I keep going in circles. I start with HBO Max app or website, choose sign-in with provider, select Xfinity, and then it tells me im trying to sign in as a secondary user. However, I have my Xfinity account pulled up on another tab and nowhere do I see anything about primary vs secondary user IDs. It's just one username which Ive been using the whole time.
Hi @Azau44, this has been cross-posted here:
In a nutshell, go to www.xfinity.com/id and use the SSN option to look up your username to sign into the correct account that's not the secondary user.