Temporarily solved the problem by giving the user access to a virtual machine with Linux instead of Windows. Probably, in my case, the problem is related to the Windows system itself.Because when I open the sound settings in the control panel, the system shows a blue screen. I answer nevertheless:
1. As a sound output, “NoMachine microphone adapter” is selected by default.Like the sound input is the same.
2. “Default communications device” selected in Skype
3. Using Skype as desktop app (not from Store)
4. Yes. I tried to restart it after the connection, without a positive result.
5. First I left it as it was, then I tried to activate other sound outputs.It had no effect.
I note that the problem is observed in any applications that receive sound from a microphone.I tried Firefox, Skype and Audacity.