Still can't enter phone numbers for call blocking - won't load - callerNumber does not match regular

Can't enter phone numbers for call blocking.

When trying to open to enter numbers, get this:

callerNumber does not match regular expression pattern

Temporarily unavailable

Sure has been temporarily unavailable for a LONG time.

Also, when trying to go to the Manage page to enter the call blocking details, the page is not found.

On this page:

https://customer.xfinity.com/MyServices/Voice

When you click Additional Voice Settings
linking to the URL https://pf.connect.comcast.net/OptimusPref/prefs/voice

You get this: Sorry, we couldn’t find that page.

I only found the call blocking options by digging through some old links.

HELP PLEASE