It doesn't seem to work even as a mp4.
Here are the 2 files....
https://drive.google.com/file/d/1PTzS-EPGo0KbBPiGmHjyV1AqU6ehvXcN/view?usp=sharing https://drive.google.com/file/d/15lx1NrhlfLd3KteCrVBEQpStLMA0Na3h/view?usp=sharing
Really weird. I can add the one file to the sequence, play it, and have no problems with the audio. As soon as I add the second video, I have an issue with the audio.
I like the program so much I will work around it. I have converted the mp4 to mp3, added the audio to the video separately, and it works just fine.