Updating the alert email addresses using the browser-based admin interface (Settings → Notifications → Notifications Email → Alert Emails → Configure) isn’t overriding/replacing old email addresses. Test emails to new addresses work every time, but alerts for actual events like a firmware update go only to an old email that isn’t listed in the Alert Configuration. This condition persists through reboots, adding back and then removing the old email, removing all emails and then adding only the new ones, etc.
