it is very hard to set a custom wallpaper on the home screen or the lockscreen, as it appears very big and with a zoom effect, this needs to be fixed as soon as possible.
If you’d like the whole photo to appear properly as your home or lock screen wallpaper, please make sure the image you’re using matches the aspect ratio of your Primebook’s display. Otherwise, the system will automatically zoom in to fit, which happens across most devices. Choosing or cropping the image to the right ratio will prevent the zoom effect.