This is actually because gnome-shell is a not fully phased update and as such appears as an available update to apt but not to update-manager which respects phasing of packages.
** Package changed: ubuntu-release-upgrader (Ubuntu) => apport (Ubuntu) ** Changed in: apport (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1872227 Title: Ubuntu bugs cannot be reported because of obsolete package versions, but everything is up-to-date To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1872227/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs