In my case (Ubuntu 20.04.1), update-notifier was being spawned every time I log in (regardless of my software update settings) due to this file:
/etc/xdg/autostart/update-notifier.desktop
This file has a "X-GNOME-Autostart-Delay=60", causing a 60-second delay, so from a user's perspective it might seem like it appears randomly, rather than being triggered due to logging in.
In case it helps someone else, you can disable this behavior by renaming the file:
In my case (Ubuntu 20.04.1), update-notifier was being spawned every time I log in (regardless of my software update settings) due to this file:
/etc/ xdg/autostart/ update- notifier. desktop
This file has a "X-GNOME- Autostart- Delay=60" , causing a 60-second delay, so from a user's perspective it might seem like it appears randomly, rather than being triggered due to logging in.
In case it helps someone else, you can disable this behavior by renaming the file:
sudo mv /etc/xdg/ autostart/ update- notifier. desktop /etc/xdg/ autostart/ update- notifier. desktop. disabled