I tested your code with several Youtube videos that are HTML5 and it worked.
It's not your code... or your animation...
I maintain a Youtube acount for Grifform Innovations and I opted into the HTML5
A lot of people have... if you right click on the video it will show if it's HTML5 or Flash
Your Youtube video is Flash it doesn't work on FF using Edge with that code...
You can append a Flash Youtube video to the Stage... that works in FF... but to any object on the Stage it doesn't work.