Note that your feedback and comments help for improvements. To improve your experience with notifications, syncing, and firmware updates, we removed the option to turn off all-day sync from the Fitbit app. When your phone is near your Fitbit device with Bluetooth turned on, it periodically syncs with the Fitbit app to update your stats and download available firmware updates. More frequent syncing rarely, if ever, noticeably decreases your device’s battery life.
You can’t transfer songs you downloaded through paid streaming services such as Apple Music and Microsoft Groove. But if you have a paid Deezer subscription, you can use the Deezer app to download playlists to your watch. For more information, I recommend visiting the following link:
How do I listen to music and podcasts on my Fitbit watch?
iTunes, to download music and podcasts to your watch, create at least 1 playlist of songs or podcasts in iTunes or Windows Media Player to download to your watch. You can confirm this in the link above.
Keep me posted.