My phone number isn't a valid number error message

I got a new phone number, but when I try to update the account, I get an error message that my phone number isn't a valid number. Trust me, it is.

I get the same error message if I try to update on the web or in the Xfinity app.

Online chat sessions are always full and it tells me to try later. I can’t even chat. I have been trying for 3 days. I give up.