HELP! After remuxing mlv to mp4 or mov it removes my Microphone Audio!

[Destructomite]

Pretty much just the title. After I remux my .mlv to .mp4 or anything else, it removes my microphone audio completely.

 

[Harold]

What program are you checking your recording with?
Are you using the manual remux or the automatic one?

 

[Destructomite]

What program are you checking your recording with?
Are you using the manual remux or the automatic one?

I've tried using VLC media player and the default Movies and TV application on Windows 10.
I'm using the manual remux option.

 

[Harold]

With VLC, are you checking for audio tracks individually?