Best AnswerI would agree about Message Plus, but doing a search I see many reports that with the latest Fitbit app this has been fixed and does work. Make sure y the app is up to date.
The app settings have to be set to show pop-ups, and the phones Sound and Notifacations needs to be set to Show on lock screen. Also on the Blaze clock face swipe down, is notifacation turned on?