It seems I've similar issue. I just installed anti-theft but cannot sign in to my avast account from within the app. It says that, "The service is temporarily unavailable. Please try again later." But each time I do so (try to sign in and receive error), it's adding another device at my.avast.com even if it's the same device. The status of the newly added device is "Offline". At one time I'd 8 entries for the same device. I've removed them all and waiting for you guys to fix it.