My ring gen 3 not detect motion

Hi All, 1st when i set up the ring gen 3, the sensor motion is good and always send me notification saying someone detected. But when the time i put on the blanket for door ( no need using screw on the door or wall). No more notification receive except people who ring the bell. Ok my questions is, is it because of my blanket causing no more motion detection ? Or is my ring got problem ? I have check thru all the settings. All goods not a problem. Could you all please teach me what should i do? I need the motion detect so much…