Microphone in Windows 10 1803 or later under VirtualBox, Ubuntu 18.10 as host.

Microphone seems not to work in any application, audio out is working in 3,5mm or in usb headset but not any mic.

1. Update Virtual Box in my case I am running 6.04
2. Install Guestadditions
3. Control panel
4. Go to privacy
5. Choose Microphone
6. Choose to use the mic in apps

Then my mic was working!