Missing sleep data
Was your ring charged enough when you went to bed? If your Sleep Card is missing sleep data, a low battery is most likely the case. It is recommended that the battery is at least 20% charged to capture a full nights sleep.
If you did not get a notification that your battery was at 20%, please check if you disabled or enabled location services. Disabling location services can interfere with syncing which can hinder notifications, so you may not have seen a notification that your battery was at 20%. We're looking at ways to further improve this experience.