I am using MSFS and have used P2A for years. My voice inputs come from the HP Reverb G2 headset, which has always worked fine. Today I loaded a flight and every time I spoke, the Echo Box repeated "then;" in green text instead of what I actually said. It didn't matter what I said, always the same THEN;. ATC chatter works and I can test the various voices and they all echo in white text. Obviously, the PTT button is working and the control panel says that the mic is working. I recently added some voices via the technique shown in the YouTube video where I add the new voices to the registry. P2A worked fine after doing that.
One change I made today, I loaded the Simshaker Sound Module and Simshaker for Aviators in anticipation of a Buttkicker arriving tomorrow. Those use the sound system, but neither is running at the moment. And they are oriented to audio Output.
So this is a mystery. If you have any suggestions.....