Microphone not working on Apple Watch

Hello,

The microphone on my Apple Watch Sport is not working. Siri doesn't respond when activated manually, no dictation, and the other party on a phone call cannot hear me.

Using iPhone 6 plus with latest iOS 9 release.

No physical damage, or water immersion. Watch looks like new even though it's worn every day.

I have done the following.

Restarted both iPhone and watch.

Force restarted both.

Unpaired and re-paired the Apple Watch from the phone.

(Of course my one year warranty ended one week ago)

Any suggestions?

Thanks,

Mike