Yeah, this video actually plays right in the web browser too, and would probably play in Quicktime etc.
Anyway, now that I see your workflow, I thought at first it was going to be because you are dragging files in right from the File Browser which I have never used before. I simply use the shortcut to Insert Audio Files and a window pops up to select the files. However, I just tried your method and I still get just two tracks.
I’m on a Mac though. I think PG will have to weigh in on this bug or loophole but if you do the Windows equivalent of SHIFT + Command + I to insert the files instead, do you get any difference.
To me this feels like a Windows specific bug or loophole that somehow you’re only experiencing or reporting.