So im on zorin so basically ubuntu with gnome. Anyway I see this thing and it only happens with firefox but the switching between various windows I get back to firefox and it will be full screen size but not actually full screened so now I can see another window peeping over the top. Does not happen consistantly at all but like a minimum of once a day I notice it and click the window back to small and then full screen again to get it to use the whole real estate. Just seeing if anyone has seen behaviour like this or better yet knows something about it.