My Nexus 5 microphone does not seem to be working while in calls. What is strange is it seems to work jsut fine when used in Skype, suggesting that this is a software issue. Also strange is that when I turn the microphone mute on/off during a call, I can hear that when the microphone is muted there is less fuzzy white noise. Has anyone encountered this issue? Is this a defective device? I've flashed this device with alternative ROMs, and now I've reflashed it with the factory stock ROM. But nothing changes the behavior that I've described.