It's a pretty minor issue, but I'm curious about why it is happening.
In GNOME Software, and in Notifications in GNOME Settings, some system applications appear twice. They don't appear twice in the application list.
Where does GNOME get its application lists from here? Synaptic reports that only one package matching
file-roller is installed.
gnome-calendar is only installed once in Apt, but is duplicated in Software.
Can this be fixed?