I use my laptop with a connected AOC ultrawide monitor as primary screen and I don’t mirror laptop screen. My system is running KDE NEON, everything updated. I have an issue when watching video in Firefox. As long as I’m watching a video on a website it works fine, but when I change the video to fullscreen the monitor just show a black screen without turning off. I tried to activate the laptop screen and it show the video I’m running in fullscreen, which should run on external monitor. So my question is, why does Firefox move the fullscreen video to the laptop screen when I don´t mirror the laptop screen to the primary screen? Hope someone can help me out.