Connecting BT domain to adobe portfolio

I am trying to connect my BT domain name to my adobe portfolio site. I follow the clear instructions on changing the DNS settings but BT have locked these to their default settings because I have BT web hosting. I then go to 'You can use an externally hosted domain name with your BT email and Web hosting services' and in put myportfolio domain name, but it keeps saying something went wrong and to check in later? I am new to this so do not know where to go from here?