macOS 10.15.5 fixed a bug in the T2 chip wherein internal speakers in sound output devices may not appear in the preferences.
Non-notarized apps were not allowed, meaning that any older audio plugin will no longer work. Catalina: Every third-party audio plugin should get “notarized” by Apple.Also, output audio devices vanished occasionally and only appeared upon restarting. Big Sur: Major issues with the Bluetooth connectivity when trying to pair audio devices to Macs.