Firefox on High Sierra not opening videos in full screen.

[I Need a Drink]

Anyone use Firefox? I've noticed that in HS, if you are not using Firefox in full screen (Green Button), if you try to watch a Youtube video in full screen it will only fill the Firefox window and you can see your desktop surrounding the video. Hope that makes sense. Safari works as it should and opens the videos in full screen. Would this be a HS issue or does Firefox need to fix this?

 

[killhippie]

Anyone use Firefox? I've noticed that in HS, if you are not using Firefox in full screen (Green Button), if you try to watch a Youtube video in full screen it will only fill the Firefox window and you can see your desktop surrounding the video. Hope that makes sense. Safari works as it should and opens the videos in full screen. Would this be a HS issue or does Firefox need to fix this?

I use Firefox and clicking full screen in the youtube video makes it occupy the whole of my 27" screen. Firefox 55.0.3

 

[Nepherte]

Anyone use Firefox? I've noticed that in HS, if you are not using Firefox in full screen (Green Button), if you try to watch a Youtube video in full screen it will only fill the Firefox window and you can see your desktop surrounding the video. Hope that makes sense. Safari works as it should and opens the videos in full screen. Would this be a HS issue or does Firefox need to fix this?

I experience the same issue. On a Macbook Pro 13" 2016 Touch Bar with macOS 10.13 and Firefox 55.0.3.

 

[RoyalStone]

Anyone use Firefox? I've noticed that in HS, if you are not using Firefox in full screen (Green Button), if you try to watch a Youtube video in full screen it will only fill the Firefox window and you can see your desktop surrounding the video. Hope that makes sense. Safari works as it should and opens the videos in full screen. Would this be a HS issue or does Firefox need to fix this?

I experience this too, but only when dock hiding is set to off. When I set dock hiding on, Firefox fills the entire screen.