Apple Watch Series 2 microphone not working

Apple Watch Series 2 microphone not working

I bought my wife and I both Apple Watch (Series 2) used just over a year ago and they worked perfectly for the first 8 months or so. Then, out of nowhere my watch would not respond to any voice commands. I can no longer use Siri, voice-to-text, answer calls, etc. My wife’s watch still works perfectly. What can I do to remedy this? The aforementioned features are THE reason why I switched from a Fitbit. Thanks for any help you can offer!