After connecting to the xFi gateway, my iphone can only get access to google and youtube but not other websites. I notice that my iphone is only assigned an ipv6 address but not a valid ipv4 address. I have requested a new gateway device but the same thing is still there. The issue started to happen a week ago after an Internet outage in my area. @ComcastJohnN Thank you.
Have you found a solution?
I have been having the exact same problem since August now, and Xfinity has been no help. It was initially affecting all my devices and remained a problem even after multiple reboots of the modem. I even swapped the modem for a new one and the problem persisted. It's a little better now in the sense that I still lose access to IPv4 websites daily, but no longer on all devices at the same time, but turning wi-fi off and on a few times on the affected device usually gets it back (for an hour maybe - never for very long). When turning wi-if off/on on the device doesn't work, finding a device for which IPv4 still works, logging into the admin portal (10.0.0.1) and manually assigning an IPv4 to the device that's not connecting also helps (though also not permanently).