I'm using a laptop that only runs libreelec, it's always connected to the TV via a VGA to HDMI converter ( VGA in pc, HDMI in TV).
I used this tutorial
To make the resolution work for the TV, I created my own edid file fitting for to my TV, and followed all the steps.
It all works I can see the kodi on my TV with great resolution (1920x1080).
However I can't get the laptop screen to go blank, and I see everything on both screens.
In the display settings the Monitor option is on "Default" if I switch it to VGA all the screens go black,
The "Black other Displays" is on (after restart as well), but I still get both screens.
Any ideas?