I opened up a game and game sounds started. All was good. Then I went back to game list, and the tab in which I originally opened the game would not stop playing game sound, until I closed it.

On our list. We will look into it.

The music stops correctly whenever we try it.
Please let us know, which operating system and web browser are you using and we can investigate it further.

Windows 8.1 - Google Chrome.

I may have been running Windows 10 when it happened. I only experienced it one singular time. Was never able to recreate it. Seems to have been a very rare occurence. If I notice it again I will note every minor aspect of my PC at the time.

Ok, thank you.
We will mark this fixed for now.