opus and mp4 not recognised

DRJ

I have a collection of opus files collected from WhatsApp voice note and this application doesn't recognise them. This application also doesn't recognise MP4 from the built-in file structure however does play from external file browsers

Developer

Opus and mp4 files will open from the "Choose a File" dialog in 6.1 beta version. The other options in the side menu won't let you select them because they're limited to what the system considers audio files.