Sonoma update blocked my Mac Studio from Xfinity Xfi Gateway

Which again points to the Xfinity firmware rather than your Mac.

Your Mac has nothing to do with Xfinity’s pause feature other than using iCloud Private Relay and/or Private Wi-Fi addressing may bypass it.

jrome wrote:

After updated to Sonoma, I had no internet.

https://discussions.apple.com/content/attachment/0022cc04-e4bc-4ae4-ad68-2e5a1e0b2196

Of course, as usual. Xfinity's help was wrong since there IS no Xfi app (it was retired). The Xfinity app said my Mac Studio was not paused. I was in captive gateway mode. I spent 4 hours with Xfinity trying to fix this, to no avail.

In desperation, I used Xfinity app to pause, and then unpause my Mac, and the Internet worked again.

This is a Sonoma bug. Nothing on the Xfinity side changed.

I post this because others might have the same issue

you can file a bug report @Apple Feedback here: Product Feedback - Apple

Literally nothing on the Mac side can cause this unless you manually set your device's MAC address to match that of a device paused when you exceed parental limits as set up on the Xfinity gateway.

Further, if you use iCloud Private Relay it may completely bypass the time limits that were set, though that's not your issue:

Apple’s new releases of iOS 15 and macOS Monterey include an internet privacy service called iCloud Private Relay. If this feature is enabled, xFi Parental Controls filtering and Active Time Details won’t work. Learn more about iCloud Private Relay.

https://www.xfinity.com/support/articles/xfinity-xfi-manage-profiles?linkId=166526317

The same is true if Private Wi-Fi Address is enabled.