Readings for body battery and stress have stopped since my last recharge this morning. Why? How do I start it up again?
Perhaps this article could help: Data is Missing from My Garmin Connect Account After Syncing | Garmin Customer Support
Another possibility is that the watch cannot measure your HRV for some reason (i.e. too much movement, wristband too loose,...). If your watch supports the feature, run a Health Snapshot, and see whether HRV is correctly measured.
