RESOLVED: Microsoft  in   their quest for an infinitely configurable machine decided to allow users to mute the microphone on any and ail apps, those designed, and those yet to be designed like WSJT-X,  They grouped LINE IN as a MICROPHONE  under a single mute button.  So, if suddenly your green monitor bar quits showing signal, it could have been muted in the following settings: SYSTEM | PRIVACY | MICROPHONE