Quoting the help files you linked to:
Stop On Page Turn
Stop playing the MP3 sound file when someone turns to a different page.
If the audio file is a non-MP3 file, this option is dimmed.
I think, that means this option is not available to movie file types.
Only for MP3 sound files.
CS6 German where the option is available and checked:
The option is still there.
Note: Since the rework of the UI with CC 2017 the option cannot be read to the end with my German UI.
And the panel cannot be expanded on width. Arrgh! Bad user experience…
The problem with that help files is:
It contains no screenshots.
You are totally correct. The option has only been available if the item is a sound file (mp3). Movies have never had it.
Regarding fitting the text in the panel, that's the problem with German. All those "Gersprechens" and "Blatumgartens" and other words I'm making up.
Thanks for your quick replies; really appreciated. I realize someone can manually stop the video using the controller skin before switching to another page, but there's no way to have it automatically stop (upon a page turn)? Is there a 3rd party plugin available that can do this? Thanks again.
Also, another quick question: which video controller would you recommend for the best user experience in an interactive PDF?
… I realize someone can manually stop the video using the controller skin before switching to another page, but there's no way to have it automatically stop (upon a page turn)?…
Not from InDesign.
Look up this functionality with Acrobat Pro DC.
Here a hint of the controls where Trevor is presenting a screenshot from Acrobat Pro.
If you are interested in an automated scripted solution, don't hold your breath: