Similar Issues with the live release.
Shortcuts will set wallpaper now, but if you have a shortcut that sets the home screen, for example, it also creates a new lock screen with no widgets and a black background (in my case as that’s what the background was when I upgraded)
Honestly, this needs fixing asap.
Also when you go and edit the new pair then the Home Screen is still black despite having a wallpaper.
Just broken.