Just reporting a minor wallpaper bug when using mosaic for two screens when you log into your desktop
you can see at the bottom where the panel is and on the right hand side the background looks like it cuts off and repeats instead of properly using mosaic. you can fix it by changing wallpaper than changing but but it does look a bit nasty and annoying to do every time you login.
Right click on screen, select Change Desktop Background, select Settings, for Picture Aspect choose either Zoom or Stretched. That should fix it.
What your dealing with here is that some, but not all, background pictures don’t have an aspect ration that naturally fills your screen. The suggested settings above compensate for that.
I changed it to those temporarily but it shouldn’t be doing this, when you set it to mosaic it all works find but once you reboot it bugs out and switching to another wallpaper than switch back fixes it on mosaic showing it’s a bug and has nothing to do with my wallpaper.