How is the notification which shows up as a red circle at the top left of the desktop version and the top right of the mobile version marked as "read"? Via cookie or a flag stored in the DB?
When I view the notification on my mobile device the indicator goes away... but when visiting the site via the desktop version the notification is there again.
Then when I drill into my account notifications are visible with a "unread" number indicator again under the "responses" area.