We acknowledge your query and apologize for the inconvenience caused to you and will surely assist you regarding the same.
The “Double-tap to wake” feature is available. Use this feature via Settings> advance features > motion and gestures > check for the 'Double-tap to wake' option.
In case the issue still occurs. Please register your concern in Samsung Members Application (Open Samsung Members Application > Support> Tap on error report > Type your query > Send).
