Query regarding audio demuxing

[Cameron Murphy]

When converting a movie like, say, Harry Potter and the Deathly Hallows Part 2 from MKV to MP4, how is it you tend to receive two (or three, depending on your preferred configurations) additional corrupt audio tracks coupled with the regular six channels?

[eumagga0x2a]

Please elaborate, especially please provide the textual output of MediaInfo for the source MKV file and the resulting MP4 from reproducing the issue you described using the latest Avidemux 64-bit nightly.

https://avidemux.org/nightly/

I tried to export the single short sample of a MKV file with HEVC as video and a 8ch DTS XLL audio track I have to MP4 and it worked just fine, producing a file playable with mpv and Avidemux with all 8 channels (QuickTime ignored the audio track, but well, it is QuickTime).