UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.76 Safari/537.36

Example URL:
youtube.com

Steps to reproduce the problem:
1. go to Youtube and watch some video
2. put the video in fullscreen
3. skip to almost the end of the video but not quite the end
4. wait for the video to finish
5. When the video is finished and you are still in fullscreen mode, click on some of the suggested videos
6. repeat steps 3 and 4
7. when the new video is finished, exit fullscreen (either via the Esc key or the fullscreen button on the bottom-right)

What is the expected behavior?
Exits fullscreen, which triggers a page reload because that's how YouTube works (you switched to another video while in fullscreen, so now it navigates to the url corresponding to the new video).

Besides that, either nothing happens, or the video starts playing again from the beginning, but either way, audio and video always go together

What went wrong?
When you exit fullscreen and the page is reloaded, you hear ONLY THE AUDIO of the video start playing again from the beginning, while the video image appears to be still paused at the end. If you click the replay button, the visible video will start playing too, and you'll be hearing two overlapping audio (one from the video you are actually playing and seeing, and one from the "ghost" video on the background). You can't in any way pause or stop the audio which keeps playing in the background.

Did this work before? No 

Is it a problem with Flash or HTML5? HTML5

Does this work in other browsers? Yes

Chrome version: 56.0.2924.76  Channel: n/a
OS Version: 
Flash Version: Shockwave Flash 24.0 r0

Contents of chrome://gpu: 

Though systematically reproducible on YouTube, it's hard to imagine even theoretically a way this could possibly be a bug in YouTube.
Also, by writing in the console: 
  $("video")
I can verify there's only one video node in the page, and it's the paused one you can see; destroying it doesn't stop the playing audio. That in itself can't be right.