Missing a night of data

The ring stores seven days of samples on board, so a night missing from the app is usually a night that has not synced yet. Open the app with the phone within a metre of the ring and wait 30 seconds; if nothing arrives, put the ring in its case for 10 seconds and take it out to restart the radio.

A ring that spins freely on the finger can also lose skin contact overnight. That leaves a real gap, which no amount of syncing will fill.