The default wallpaper for a user will automatically be set at the first login after install.
The Deepin desktop no more sets the wallpaper. We have been using these commands (which now fail):
pic=/usr/share/endeavouros/backgrounds/endeavouros-wallpaper.png dconf write /com/deepin/wrap/gnome/desktop/background/picture-uri "'$pic'"
The reason is unknown, so any help with this issue would be greatly appreciated.
Note that with the GUI based tools of Deepin the wallpaper can be set as expected.