They may have failed to transfer the UserIDs/logins/email addresses from the old account to the new one. You can check the UserIDs by bringing up the list at https://idm.xfinity.com/myaccount/lookup on your home Internet connection. If your old IDs aren't listed, you'll need to get them to fix it.
Hi Mysterymike, thank you for reaching out and I can review this for you. Please send me a private message with your account information (your name, and phone number).