youtube-dl-gui allows choosing to download a video as an .mp4 file or an .mkv file. According to VLC, both options end up having the audio portion encoded as Opus audio. However, attempting to play the .mp4 version with Windows 11's new media player results in it complaining:
We can't play the audio for filename.mp4. It's encoded in Opus format which isn't supported. You can still watch the video.
Playing the .mkv version with the new Windows 11 media player works perfectly fine, though, despite both versions having Opus audio (according to VLC, at least).
Is there anything I can do to get it to play back the .mp4 version as well?