Additional off-screen selections with latest version
When using multiple screens, selecting multiple items via mouse by dragging the "selection rectangle" above them, produces additional selection lines on other screens.
This also happens by simply creating a selection rectangle on desktop - see pictures below.
Issue can be resolved by downgrading to previous version (16) from https://extensions.gnome.org/extension/2087/desktop-icons-ng-ding/
Edited by John Doe