What is the black oval on Liberty 3 Pro's earbuds?
They are the IR-sensors which sense if the earbuds are currently being worn. If the ear wings are installed incorrectly, the sensor will be covered and it will affect the accuracy of wearing detection. Make sure the ear wings are installed correctly and the surface of the IR-sensors is kept clean.
If you have additional questions, please contact us at service@soundcore.com for further assistance.