Using the latest version on Windows 10 x64.
I have a Logitech G933, and I have no input nor output audio with it. No input audio with my webcam either. I've tried with the Logitech Gaming Software running and stopped, no audio in both cases.
The only case I can get some audio to work is if I select one of my screens as the ouput device.
All other apps are able to use the headset (both mic and speakers) just fine. Only Zoiper isn't.