If your Smart Sock is unable to detect the baby’s heart rate, please check the following details to verify if the issue can be resolved.
 

Intense Movements

If there are intense movements, it may cause the Smart Sock to be unable to detect the baby's heart rate.

Abnormal WiFi network connection

When the WiFi network is either unstable or unavailable, the recorded data will not be uploaded to the eufy Baby app.

Low battery shutdown

The Smart Sock will automatically turn off due to low battery in order to preserve its battery life.

Smart Sock fell off

The baby may have kicked the Smart Sock off while moving. Please note that if the Smart Sock falls off, the baby’s heart rate cannot be detected.

False detection

The Smart Sock uses optical reflection in order to detect accurate heart rate readings. In certain rare instances, such as when the sensor is facing a light or reflective surface, there is a slight chance that the Smart Sock may not be able to detect accurate heart rate readings.

Sensor failure

The Smart Sock will not be able to detect or provide accurate heart rate readings when the Smart Sock is submerged in water for a long period of time, or if the sensor on the Smart Sock is dirty and covered by other objects.