I am using 2 monitors. Usually I use first to watch a stream or videos (youtube) and the other to other things. When I switch from stream window to other window, the stream is stopping (like stop buffering) and when I get back stream is immediately starts. There's no problem if I stay within the same firefox window, switching tabs only. Audio is always turn on (I know about stoping media while audio is off and tab is inactive). How to solve this? I couldn't find any setting about this issue.