When using NDI Scan Converter as a video streaming source with Playback, it’s important to make sure that the audio is muted in the NDI application. (Settings > Mute Audio)

Since NDI is being used just as video source, it’s important to mute the audio from the app, otherwise, Playback will receive the system audio redundantly (x2) which may cause feedback issues.

This is important for those that might be using Adobe Premier, Final Cut, etc.