The same happen to me since Juno, with Loki I could without issue. Now is not possible to upscale any video content The only way to bypass it is to maximize it/go fullscreen on the main display and then send it to the desired one (winkey+shift+right_arrow) I couldn't figure out where to watch in the logs to check what happen -- I use chrome to watch netflix and youtube in kiosk mode just save the app shortcut then edit it and add **--kiosk** and **--window-position=X,0** where **X** stand for the x coordinate where the second display starts https://peter.sh/experiments/chromium-command-line-switches/ check your displays with: **$ xrandr --query** that will make chrome go fullscreen and load on the second display for youtube -> youtube.com/tv (works awesome)