Parental Controls not blocking one website

Thanks for responding, but I'm not sure if I understood your suggestion.

I don't see a way to add a customer rule. 

Meanwhile, the website I am blocking do not forward to any other website. It's just that website - which I see on the blocked list, but which isn't being blocked when I look above at the URL

Note that I have no trusted devices. All websites on the blocked list should be blocked on all devices.

Hello SAS29485, yes the Blocked Websites list will affect all devices connected to the modem, as it should.  I suggested the Blocked Devices section as an alternate method potentially for bolstering security to a single device. This can also be used to make exceptions and allow website access as needed. 

Multiple IP addresses from the same site may be why this is not showing as completely blocked, but the admin portal is working as intended. 

Thank you for sharing that screenshot, @SAS29485! You are correct that the 'My xFi' site is no loner operational. All of those functions have been transferred to the Xfinity app.

Where do I find Manage Device on the App? And then how do I add a custom rule?

@SAS29485 Please visit this link to learn how to manage the devices connected to your network https://www.xfinity.com/support/articles/xfinity-xfi-manage-profiles.

I was able to go on the App and assign device to one person, and then add Parental Controls. However, it doesn't block some of the most well known sexual content websites at all. At least the URL blocking on the router blocks most of those. So I'm not sure of the Parental Controls works. It's been now 24 hours since I turned it on.

Thank you for getting back to us, @SAS29485. The best description I could find for parental controls was on our support site here: https://www.xfinity.com/support/articles/managing-devices-with-xfi-faqs

"Comcast has engaged a third-party vendor who maintains a database that maps online content to a set of over 400 categories, such as social media, automotive, gambling, violence, adult content and more. Based on industry standards, best practices and experience, our vendor has recommended which categories are generally deemed appropriate for all ages. Content deemed as appropriate generally does not include profanity, sexual content, violence, child abuse, software piracy, copyright theft, malware, spyware, depictions of alcohol, tobacco, weapons, gambling or drug use. Content mapping is updated regularly by the vendor to help ensure a comprehensive list is maintained."

It sounds like the block is more generic in nature, and may not block access to all inappropriate sites and applications, compared to the URL blocking from your router, but it is definitely good to have it in place. The Xfinity app also allows you to set downtime schedules and pause access to individual devices or users as necessary. I've used this feature for the last few years to prevent my children from going online after bedtime and during family meals. It's been very helpful.