Following https://volumio.org/raspberry-pi-display-and-volumio-touchscreen-music-player/ I purchased a https://ameridroid.com/products/odroid-vu7-plus-7-inch-hdmi-display-with-multitouch.
I cannot get the screen to work properly. Here is what happens (in the images below you need to scroll through them to see the entire screen).
When plugged into my monitor, it works fine (below right). If I then unplug it from the monitor and plug it into the 7" screen it displays but in the wrong resolution (cutting off the screen on the left) and touch does not appear to work (below, right).
When I boot with the 7" screen plugged in I get a screen that only displays a line when the mouse is moved (see below left).
If I then unplug the 7" and plug in the monitor it displays Volumio as if it was on a small screen (below right) i.e. it saw the 7" screen.
Am I doing something wrong?