Usually, when a vibration, door, or kettle sensor is triggered, it will take between 10 and 15 minutes to show the data on the dashboard or the app.
The wearable stores data internally, and then uploads it back to the home hub, so it can take a little longer to appear, depending on how far the wearable is from the home hub.
The sleep sensor will only trigger after a certain amount of time detecting pressure (to avoid picking up items being placed on the bed for example). So data may not appear immediately, and will likely appear within 30 minutes of someone getting into bed.