That testing world is modified from your video sample 2.
I have tested on Android and iPhone.
about 5 years ago
It looks to me as if you are starting the video with play(-1). -1 is the loop count and in this case means loop the video infinitely. As the video will never finish playing the trigger won't be called.
Exchange play(-1) with play(1) or just play() to play it only once. This should fire the onFinishedPlaying trigger.