Microphone not working in sandboxed Electron app (Webcord)

Discussed in https://github.com/sandboxie-plus/Sandboxie/discussions/1118 and https://github.com/SpacingBat3/WebCord/discussions/68

Originally posted by @Hackelhack - August 17, 2021 Webcord (https://github.com/SpacingBat3/WebCord) An exceptional more private alternative to the Discord app has odd microphone issues. I'm personally aware of the bugs that electron has with microphone access - but none of the workarounds seem to fix it.

While sandboxed, the electron app Webcord fails to get access to the microphone. You cannot unmute in the discord GUI. Oddly, in settings when testing the microphone, you can still hear the feed just fine. Just only when testing in the settings.