Cannot connect to "Xfinity Mobile" WiFi hotspot

I am an Xfinity Internet customer but not an Xfinity Mobile customer. I used to be able to connect my iPhone (or iPad) automatically to the "XFINITY" WiFi hotspot, but the name of those seems to have to changed to "Xfinity Mobile." Now I cannot connect my iPhone to the "Xfinity Mobile" hotspot. I have removed the Xfinity security profile from my devices and tried to reinstall them with the Xfinity app, but still no joy.

The various Xfinith web pages (such as https://www.xfinity.com/support/articles/about-xfinity-wifi-internet and https://www.xfinity.com/support/articles/about-xfinity-wifi-internet) do not draw any distinction between the ability to connect to "xfinitywifi," "XFINITY," or "Xfinity Mobile," except that to use the latter two, I need to install a security profile (which the Xfinity app is supposed to do for me).

I want to be able to use the "Xfinity Mobile" hotspots where they are available because they are secure and the "xfinitywifi" one is not. And so far, none of the Xfinity support people with whom I've spoken can tell me why I am not able to do this.

Any suggestions?