NotAuthenticated when trying to login

Exactly one month ago (on September 11th) I made a tenancy deletion request. I read that tenancy deletion request may take up to 30 days. However, on September 14th I got an email saying this: "Your tenancy has been permanently deleted". After that email I still got the same error:

{
  "code" : "NotAuthenticated",
  "message" : "The required information to complete authentication was not provided or was incorrect."
}

I tried today to log in with no success as I got the same error as previously. I tried to generate a Bypass code as I read that there may be problems with my 2FA code, however, I still wasn't able to log in.