Hi katariyajain, Make sure you are on the latest software version which is .151 if not, you can check by Go to setting => System => About => Software information. Check if the screen guard is not covering the top portion where the proximity sensor is placed.
@ARP_ASUS Hi, I am also facing the same problem. This started happening after the .151 update. How do I report to Asus because there are more bugs? The air triggers are not giving feedback anymore, also no vibration when I am receiving calls. I've already done a factory reset. Nothing happened.