I noticed that j_campbell responded to my questions by saying,

hasn't stopped for me at 3:02, other than the music stopping.

Hmmm ... the audio track is 3:02, ... right? 

Sometimes these things have to do with your browser memory cache
needing to be cleared.

Maybe sometimes ... but not this time. 

I cleared the cache and the playback still stopped at 3:02

Earlier today, you said,

I found a way to solve the sound problem. ...  If I open my file and
separate the audio and video files and reprocess it as an mp4 and
not a mov file then when I upload it their processing works fine.

Just a suggestion, but what if you did that additional processing and
uploaded the result as a new video to YouTube.  By doing that you
would know if the video stop at 3:02 was also fixed.  This presumes
that you could also delete that (possibly) unwanted/unnecessary video
from YouTube. 

HTH

--
Martin