Apple ID Sign-In authentication failure message
Cannot sign into iCloud on any device (iPad 11 pro, mbp15, iPhone x) when prompted to manage subscriptions, or to download anything from the AppStore. I get an alternation of "Authentication failed" & "An unexpected error has occurred".
I've sent an email to apple support, and will be awaiting their response - but I figured I'd post something here to see if anyone has had a similar issue or if anyone may know a solution.
[Re-Titled by Moderator]