Thanks Jeremy, looks like both Quicktime and MPEG Streamclip are reading the file as 56:49:09. I’m starting to think that this might be a problem of drop frame editing vs non-drop frame. While this chart refers to footage that is 29.97 the info might still be applicable: https://documentation.apple.com/en/finalcutpro/usermanual/index.html#chapter=D%26section=6%26tasks=true
You’ll see that an hour long program turns out to be about 3.6 seconds longer in real time. Now the question, how do you get the FCPX timeline to display the drop frame timecode?
Thanks for the response. The audio is flush with last frame of video. Unfortunately the range selector did not solve the issue. The export window time matches the duration in the timeline 56:46;00.