Comment 6 for bug 1870956

If the mouse leaves the highlighted icon by moving over a window without touching the desktop, the icon highlight also remains. This problem has been fixed in Ubuntu 22.04, with the following packages:

$ dpkg -l |grep gnome |grep desk
ii gir1.2-gnomedesktop-3.0:amd64 42.0-1ubuntu1 amd64 Introspection data for GnomeDesktop (GTK 3)
ii gnome-calculator 1:41.1-2ubuntu2 amd64 GNOME desktop calculator
ii gnome-control-center 1:41.4-1ubuntu13.2 amd64 utilities to configure the GNOME desktop
ii gnome-control-center-faces 1:41.4-1ubuntu13.2 all utilities to configure the GNOME desktop - faces images
ii gnome-desktop3-data 42.0-1ubuntu1 all Common files for GNOME desktop apps
ii gnome-menus 3.36.0-1ubuntu3 amd64 GNOME implementation of the freedesktop menu specification
ii gnome-online-accounts 3.44.0-1ubuntu1 amd64 service to manage online accounts for the GNOME desktop
ii gnome-power-manager 3.32.0-2build2 amd64 power management tool for the GNOME desktop
ii gnome-remote-desktop 42.0-4ubuntu1 amd64 Remote desktop daemon for GNOME using PipeWire
ii gnome-shell 42.0-2ubuntu1 amd64 graphical shell for the GNOME desktop
ii gnome-shell-extension-desktop-icons-ng 43-2 all desktop icon support for GNOME Shell
ii gnome-todo 3.28.1-6ubuntu1 amd64 minimalistic personal task manager designed to fit GNOME desktop
ii libgnome-desktop-3-19:amd64 42.0-1ubuntu1 amd64 Utility library for the GNOME desktop - GTK 3 version
ii libgnome-desktop-4-1:amd64 42.0-1ubuntu1 amd64 Utility library for the GNOME desktop - runtime files