I'm still not sure how I managed to actually log on to the forums, because for the last five minutes every time I enter my email in the username field, when I hit enter I get the message "Personal accounts are no longer supported."
Try clearing your browser cache or a new browser. I am able to sign in with a personal account. I have an email associated with a personal and corporate account, it asks me which login to use. In the forum I always use the personal account. However, I do have 2FA turned on. I don't know if it makes a difference.