Turn Off Ubuntu Automatic Updates
Edit both files :
/etc/apt/apt.conf.d/10periodic /etc/apt/apt.conf.d/20auto-upgrades
And change to 0
APT::Periodic::Update-Package-Lists "0";
References
https://www.garron.me/en/linux/turn-off-stop-ubuntu-automatic-update.html
https://askubuntu.com/questions/172524/how-can-i-check-if-automatic-updates-are-enabled
https://linuxconfig.org/disable-automatic-updates-on-ubuntu-18-04-bionic-beaver-linux