Default [Q] Zte Open C Proximity Sensor problem

Hello I bought this phone last week and I realized that there are problems with the proximity sensor. When I make a call the screen does not turn off the phone closer to my face. And after it goes out to set time off to end the phone call must again press the power button.
I tried also with Android rom 4.4.2 and the probleme is the same.
If I go into test mode by typing the dialer *983*0# there is no way to test the proximity sensor, accelerometer sensor only
Have you encountered this problem ? or phone does not have the proximity sensor