Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
HBO says that HBO Max is available to people who subscribe to HBO through Verizon Fios. So you should be able to watch it with the Roku, just like you were previously with HBO Go and HBO now.
I was able to do those things previously. I’m also able to log into HBO Max on a computer. I believe the design is that I SHOULD be allowed to access HBO Max through the Roku. I believe that is the intent of HBO.