I've got Comcast internet service, and when I initially connect to a "Xfinitywifi" hotspot it will bring up a startup screen asking for a Comcast username and password. After that point I don't need to do that any more, as their system is supposed to remember the MAC address of the WiFi connection. Occasionally I'll connect and see a brief, disappearing popup that says "You're connected". There are complaints about this.
https://www.reddit.com/r/Comcast/comments/666tl4/how_to_remove_the_xfinitywifi_l ogin_popup/
Not sure what's happening with your setup though.
Why do my MacBook pro get Xfinity wifi free?? No sign in, no hour pass, it's just free.
