Picked up a brand new Verizon iPhone 6 64GB, and having intermittent mic problem. Example: when trying to talk to siri, phone not picking up the voice. I thought the phone is stuck thinking there's a headset plugged in. Hard reboot fixes the problem until it shows up again next time. Next to try is DFU. I'm not having this issue on the iPhone 6 Plus. Is this a software thing or perhaps more of a hardware problem?