Update Manager notification never pop up.

I tested with a fresh installation of Ubuntu 24.04.1 LTS and 24.10
Both using the same configuration on update-manager with Immediately notify.

Only on the LTS release update-manager works as expected and pop up after a couple of seconds when you reboot the system.

So there is something wrong with the non-lts releases that prevent update-manager to pop up despite the confguration. You need to execute it manually.

Here are some logs when I executed update-manager via cli in 24.10:

WARNING:root:can not import unity GI Namespace Dbusmenu not available
/usr/lib/python3/dist-packages/uaclient/apt.py:299: Warning: W:Unable to read /var/lib/ubuntu-advantage/apt-esm/etc/apt/apt.conf.d/ - DirectoryExists (2: No such file or directory)
  apt_pkg.init()
/usr/lib/python3/dist-packages/uaclient/apt.py:281: Warning: W:Unable to read /var/lib/ubuntu-advantage/apt-esm/etc/apt/sources.list.d/ - DirectoryExists (2: No such file or directory), W:Unable to read /var/lib/ubuntu-advantage/apt-esm/etc/apt/sources.list - RealFileExists (2: No such file or directory), W:Unable to read /var/lib/ubuntu-advantage/apt-esm/etc/apt/preferences.d/ - DirectoryExists (2: No such file or directory)
  apt_pkg.init_system()

Output from 24.04.1 LTS:

WARNING:root:can not import unity GI Namespace Dbusmenu not available
WARNING:root:Error loading .desktop file /usr/share/ubuntu/applications/texdoctk.desktop: constructor returned NULL

Thank you for the report. Can you please post the output of 'apt list --upgradable' in the affected system?

sudo apt list --upgradable

alsa-ucm-conf/oracular-updates,oracular-updates 1.2.10-1ubuntu6.2 all [actualizable desde: 1.2.10-1ubuntu6.1]
brave-browser/stable 1.73.104 amd64 [actualizable desde: 1.73.91]
cloud-init/oracular-updates,oracular-updates 24.4-0ubuntu1~24.10.1 all [actualizable desde: 24.4~3+really24.3.1-0ubuntu4]
code/stable 1.96.2-1734607745 amd64 [actualizable desde: 1.95.3-1731513102]
containerd.io/oracular 1.7.24-1 amd64 [actualizable desde: 1.7.23-1]
curl/oracular-updates,oracular-security 8.9.1-2ubuntu2.2 amd64 [actualizable desde: 8.9.1-2ubuntu2.1]
docker-buildx-plugin/oracular 0.19.3-1~ubuntu.24.10~oracular amd64 [actualizable desde: 0.17.1-1~ubuntu.24.10~oracular]
docker-ce-cli/oracular 5:27.4.1-1~ubuntu.24.10~oracular amd64 [actualizable desde: 5:27.3.1-1~ubuntu.24.10~oracular]
docker-ce-rootless-extras/oracular 5:27.4.1-1~ubuntu.24.10~oracular amd64 [actualizable desde: 5:27.3.1-1~ubuntu.24.10~oracular]
docker-ce/oracular 5:27.4.1-1~ubuntu.24.10~oracular amd64 [actualizable desde: 5:27.3.1-1~ubuntu.24.10~oracular]
docker-compose-plugin/oracular 2.32.1-1~ubuntu.24.10~oracular amd64 [actualizable desde: 2.29.7-1~ubuntu.24.10~oracular]
firmware-sof-signed/oracular-updates,oracular-updates 2024.06-1ubuntu1.1 all [actualizable desde: 2024.06-1ubuntu1]
fwupd/oracular-updates 1.9.27-0ubuntu1~24.10.1 amd64 [actualizable desde: 1.9.24-1]
gir1.2-gst-plugins-base-1.0/oracular-updates,oracular-security 1.24.8-1ubuntu0.1 amd64 [actualizable desde: 1.24.8-1]
gir1.2-gstreamer-1.0/oracular-updates,oracular-security 1.24.8-1ubuntu0.1 amd64 [actualizable desde: 1.24.8-1]
gir1.2-gtk-4.0/oracular-updates 4.16.3+ds-0ubuntu1 amd64 [actualizable desde: 4.16.2+ds-2]
gir1.2-javascriptcoregtk-4.1/oracular-updates,oracular-security 2.46.4-0ubuntu0.24.10.1 amd64 [actualizable desde: 2.46.3-0ubuntu0.24.10.1]
gir1.2-mutter-15/oracular-updates 47.0-1ubuntu4.1 amd64 [actualizable desde: 47.0-1ubuntu4]
gir1.2-packagekitglib-1.0/oracular-updates 1.3.0-1ubuntu1 amd64 [actualizable desde: 1.3.0-1]
gir1.2-webkit2-4.1/oracular-updates,oracular-security 2.46.4-0ubuntu0.24.10.1 amd64 [actualizable desde: 2.46.3-0ubuntu0.24.10.1]
google-chrome-stable/stable 131.0.6778.204-1 amd64 [actualizable desde: 131.0.6778.85-1]
gstreamer1.0-alsa/oracular-updates,oracular-security 1.24.8-1ubuntu0.1 amd64 [actualizable desde: 1.24.8-1]
gstreamer1.0-gl/oracular-updates,oracular-security 1.24.8-1ubuntu0.1 amd64 [actualizable desde: 1.24.8-1]
gstreamer1.0-packagekit/oracular-updates 1.3.0-1ubuntu1 amd64 [actualizable desde: 1.3.0-1]
gstreamer1.0-plugins-base-apps/oracular-updates,oracular-security 1.24.8-1ubuntu0.1 amd64 [actualizable desde: 1.24.8-1]
gstreamer1.0-plugins-base/oracular-updates,oracular-security 1.24.8-1ubuntu0.1 amd64 [actualizable desde: 1.24.8-1]
gstreamer1.0-plugins-base/oracular-updates,oracular-security 1.24.8-1ubuntu0.1 i386 [actualizable desde: 1.24.8-1]
gstreamer1.0-plugins-good/oracular-updates,oracular-security 1.24.8-1ubuntu1.1 amd64 [actualizable desde: 1.24.8-1ubuntu1]
gstreamer1.0-plugins-good/oracular-updates,oracular-security 1.24.8-1ubuntu1.1 i386 [actualizable desde: 1.24.8-1ubuntu1]
gstreamer1.0-pulseaudio/oracular-updates,oracular-security ...

This is the log from a ubuntu plucky installation on a VM:

sudo apt list --upgradable
alsa-ucm-conf/plucky 1.2.12-1ubuntu1 all [upgradable from: 1.2.12-1]
apport-core-dump-handler/plucky 2.31.0-0ubuntu2 all [upgradable from: 2.30.0-0ubuntu5]
apport-gtk/plucky 2.31.0-0ubuntu2 all [upgradable from: 2.30.0-0ubuntu5]
apport/plucky 2.31.0-0ubuntu2 all [upgradable from: 2.30.0-0ubuntu5]
appstream/plucky 1.0.4-1 amd64 [upgradable from: 1.0.3-1]
apt-config-icons-hidpi/plucky 1.0.4-1 all [upgradable from: 1.0.3-1]
apt-config-icons/plucky 1.0.4-1 all [upgradable from: 1.0.3-1]
aptdaemon-data/plucky 2.0.1 all [upgradable from: 1.1.1+bzr982-0ubuntu47]
aptdaemon/plucky 2.0.1 all [upgradable from: 1.1.1+bzr982-0ubuntu47]
avahi-daemon/plucky 0.8-14ubuntu1 amd64 [upgradable from: 0.8-13ubuntu6]
bash/plucky 5.2.37-1ubuntu1 amd64 [upgradable from: 5.2.32-1ubuntu2]
binutils-common/plucky 2.43.50.20241215-1ubuntu1 amd64 [upgradable from: 2.43.50.20241204-2ubuntu1]
binutils-x86-64-linux-gnu/plucky 2.43.50.20241215-1ubuntu1 amd64 [upgradable from: 2.43.50.20241204-2ubuntu1]
binutils/plucky 2.43.50.20241215-1ubuntu1 amd64 [upgradable from: 2.43.50.20241204-2ubuntu1]
cpp-14-x86-64-linux-gnu/plucky 14.2.0-11ubuntu1 amd64 [upgradable from: 14.2.0-9ubuntu1]
cpp-14/plucky 14.2.0-11ubuntu1 amd64 [upgradable from: 14.2.0-9ubuntu1]
dnsmasq-base/plucky 2.90-6ubuntu1 amd64 [upgradable from: 2.90-5]
dracut-install/plucky 105-2ubuntu5 amd64 [upgradable from: 105-2ubuntu3]
enchant-2/plucky 2.8.2+dfsg1-1 amd64 [upgradable from: 2.3.3-2build2]
espeak-ng-data/plucky 1.52.0+dfsg-4 amd64 [upgradable from: 1.51+dfsg-12build1]
ethtool/plucky 1:6.11-1 amd64 [upgradable from: 1:6.10-1]
firmware-sof-signed/plucky 2024.06-1ubuntu3 all [upgradable from: 2024.06-1ubuntu2]
gcc-14-base/plucky 14.2.0-11ubuntu1 amd64 [upgradable from: 14.2.0-9ubuntu1]
gdb/plucky 15.2-1ubuntu2 amd64 [upgradable from: 15.1-1ubuntu2]
gettext-base/plucky 0.22.5-3 amd64 [upgradable from: 0.22.5-2]
gir1.2-freedesktop/plucky 1.82.0-3 amd64 [upgradable from: 1.82.0-2]
gir1.2-girepository-2.0/plucky 1.82.0-3 amd64 [upgradable from: 1.82.0-2]
gir1.2-glib-2.0/plucky 2.82.4-1 amd64 [upgradable from: 2.82.2-3]
gir1.2-gtk-4.0/plucky 4.17.1+ds-2 amd64 [upgradable from: 4.16.7+ds-1]
gnome-calculator/plucky 1:47.1-1ubuntu1 amd64 [upgradable from: 1:47.0-2ubuntu2]
gnome-initial-setup/plucky 47.2-1ubuntu2 amd64 [upgradable from: 47.2-1ubuntu1]
gstreamer1.0-pipewire/plucky 1.2.7-1ubuntu3 amd64 [upgradable from: 1.2.7-1]
gstreamer1.0-plugins-good/plucky 1.24.10-1ubuntu2 amd64 [upgradable from: 1.24.10-1ubuntu1]
gtk-update-icon-cache/plucky 4.17.1+ds-2 amd64 [upgradable from: 4.16.7+ds-1]
hunspell-en-gb/plucky 1:24.8.4-1 all [upgradable from: 1:24.8.3-1]
hunspell-en-za/plucky 1:24.8.4-1 all [upgradable from: 1:24.8.3-1]
hunspell-es/plucky 1:24.8.4-1 all [upgradable from: 1:24.8.3-1]
iputils-ping/plucky 3:20240905-1ubuntu1 amd64 [upgradable from: 3:20240117-1build1]
iputils-tracepath/plucky 3:20240905-1ubuntu1 amd64 [upgradable from: 3:20240117-1build1]
laptop-detect/plucky 0.16+nmu1 all [upgradable from: 0.16]
libappstream5/plucky 1.0.4-1 amd64 [upgradable from: 1.0.3-1]
libatomic1/plucky 14.2.0-11ubuntu1 amd64 [upgradable from: 1...

I think there is a problem with the repository refresh not triggering correctly, because when I manually execute apt update, after a couple of seconds the update-notifier is showing the update list.

I can confirm the same behavior on my machine

/usr/lib/update-notifier/apt-check:351: Warning: W:Unable to read /var/lib/ubuntu-advantage/apt-esm/etc/apt/apt.conf.d/ - DirectoryExists (2: No such file or directory)
  apt_pkg.init()
/usr/lib/update-notifier/apt-check:359: Warning: W:Unable to read /var/lib/ubuntu-advantage/apt-esm/etc/apt/sources.list.d/ - DirectoryExists (2: No such file or directory), W:Unable to read /var/lib/ubuntu-advantage/apt-esm/etc/apt/sources.list - RealFileExists (2: No such file or directory), W:Unable to read /var/lib/ubuntu-advantage/apt-esm/etc/apt/preferences.d/ - DirectoryExists (2: No such file or directory)
  apt_pkg.init()

The list of the upgradeable packages was:

gdm3/oracular-updates 47.0-1ubuntu2.24.10.1 amd64 [poate fi înnoit de la: 47.0-1ubuntu2]
gir1.2-gdm-1.0/oracular-updates 47.0-1ubuntu2.24.10.1 amd64 [poate fi înnoit de la: 47.0-1ubuntu2]
libgdm1/oracular-updates 47.0-1ubuntu2.24.10.1 amd64 [poate fi înnoit de la: 47.0-1ubuntu2]
ubuntustudio-pipewire-config/oracular-updates,oracular-updates 24.10.27.1 all [poate fi înnoit de la: 24.10.27]

Any fixes yet?