I have tested also using Hype Reflect and this produces the same condition (Video does not show but button animation confirms playing is happening).
I have a new isolated file for testing:
Mark, using your tip the plugged in iPhone briefly flashed and it's presence on the Mac using Safari and the Develop drop down. Flashed meaning, it showed when initially connecting then when iTunes did it's automatic inclusion of the new connected device it was no longer present.
I've also used the Develop drop down to select a User Agent but that still shows the video properly and does not accurately reflect the iOS case even when that selection is made.
You said a number of errors were present. What were they?