Hello @JoostT
I don't think you're doing anything wrong or don't have the correct notification settings. I looked at Fitbit Notifications in the Fitbit app, but didn't see one for Step streak. So, that's likely the reason why you haven't gotten a notification.
By the way, I also checked the available Fitbit badges. There's one for lifetime miles and steps in a day. But I don't see one for Step streak.
Rieko | N California USA MBG PE
Best Answer