C4001 mmWave sensor

Well first test. I connect to my phone for receiving data and got outdoor. Sensor is about 1.5m from the floor.

I constantly got that something is in font me. Ghost perhaps? What do I do wrong. I simply read data from sensor. 
If I try in my room, results are better. It will detect my presence, It also measures the distance correctly.
Why outside doesn't work??? I will need this sensor for outside work!