I have started getting this problem after the Lollipop udate to 14.5.A.0.270 (which is strange since a another thread is speaking of that particular build to be the problem resolution). Now the sensor works randomly. My impression is that it works more often than not, but it's very annoying when I accidentally change settings during calls, when my ear touch the screen. What usually happens is that the shortcuts in the pulldown menu gets activated (wifi, hotspot, screen light, rotate screen, flight mode etc)
I haven't made any other changes to the phone and I don't have a screen protector on it. The sensor has always worked perfectly since I bought it about a year ago. I can only assume it is sw related.
