The dynamic wallpaper change does only seem to work for me if I use wallpapers from the "Wallpaper" category. If I choose a wallpaper from "Picture Folder", then "org.gnome.desktop.background.picture-uri" points to a file in ~/.cache/gnome-control-center/backgrounds/, x-0-greeter.log suggests a permission problem, and I get the default wallpaper.
And indeed, ~/.cache has a 700 permission (at least on three systems I checked). If I manually set the gsetting key to a file in ~/Pictures, the wallpaper change works fine.
The dynamic wallpaper change does only seem to work for me if I use wallpapers from the "Wallpaper" category. If I choose a wallpaper from "Picture Folder", then "org.gnome. desktop. background. picture- uri" points to a file in ~/.cache/ gnome-control- center/ backgrounds/ , x-0-greeter.log suggests a permission problem, and I get the default wallpaper.
And indeed, ~/.cache has a 700 permission (at least on three systems I checked). If I manually set the gsetting key to a file in ~/Pictures, the wallpaper change works fine.