Having trouble setting up iCloud Mail account via web browser

Everything was going smoothly at first. I created an iCloud account using my email and password and that worked fine. Then, I tried to create an iCloud mail account. I put in the credentials of my iCloud account, but afterward, when it was supposed to bring me to the page that says "set up iCloud mail", the page only flashed by for about a 4th of a second before sending me back to the login screen. I've tried this multiple times on multiple different browsers and devices. It kept doing the same thing. I can't proceed with setting up the account if I can't properly access the next page.