Issue Description
A wallpaper is included on the blueprint assigned to a device, but the device does not have the wallpaper/background.
Troubleshooting Steps
Ensure all device requirements are met:
Device must be supervised.
If not supervised, you can gain supervision by following Supervising Mobile Devices with Apple Configurator however this requires wiping the device.
Image files are PNG or JPEG, and a maximum of 4MB.
Try testing with a different image to see if the issue is specific to the Wallpaper image file used.