I see the message about working on sync issues with Android. Are you also aware of issues with iOS? We have 2 different Fitbit devices in the house. Starting on 6/23 neither would sync when phones were connected to WiFi (although other things connected to WiFi are working fine so WiFi isn’t the issue). I’ve shut down the app, turned WiFi off & back on, disconnected the device and set it back up, and deleted & reinstalled the app. Nothing works but it will sync fine if I’m connected to cellular.
