1. Please wear the Watch correctly.
2. Turn on heart rate measurement, and check if the indicator light on the case back of the Watch is flashing. If it is not flashing, we recommend that you press the button on the Watch to enter Settings--System Menu, then click Restart. Or, long press the button, then click Restart, and use it again to check.
3. To experience the latest firmware features, you can upgrade the firmware to the latest version in the app. To do this, open the app, go to the Device page, and click Device Upgrade.
4. If the above steps do not resolve the issue, press the button on Watch to enter Settings--System Menu. Click Reset. Then, check again to see if the issue is resolved.