jQuery("video").on('play', function() does not run when video is played

Hello,
I'm trying to get a timestamp when a participant starts watching a video. I'm using Vimeo to upload my videos and embed them in the survey. For some reason, the function jQuery("video").on('play', function()  does not run when the video is played. Maybe it is somehow related to using Vimeo?
I'm using the following code:
Qualtrics.SurveyEngine.addOnReady(function()
{
    var s='';
    alert(Date.now())
    jQuery("video").on('play', function() {
alert(Date.now())
      if(s==''){
      s= Date.now();
         Qualtrics.SurveyEngine.setEmbeddedData( 'Vid1PlayTime', s);
      }
    });
});