Wallpaper swap

I use Teamviewer 13 for a Remote Console to access my 3 other computers from my laptop. The laptop & one other computer are running Windows 10. Lately these two computers have been swapping the wallpaper backgrounds on the desktop. The normal wallpaper on the laptop is the one that came with it 7 years ago with Windows 7 Pro and was never stored on the other computer. I don't know how the swap is taking place. Bob B.