So, sometimes after I open up my MBP and wake it from sleep, the login screen has an all-grey wallpaper. Sometimes it has the mesh-fabric style wallpaper. And sometimes it has the stock Milky Way image for the wallpaper. Anyone experience the same thing? I really dislike the Milky Way image for a wallpaper and would like to set it to not be that, but can't find where to change wallpapers other than for the desktop. Any help would be great.