I've a Thinkpad s440 with an old Ubuntu 16.04 installation that always worked fine.
Today, just after install SQL Server for Linux and run:
sudo apt-get update
sudo apt-get upgrade
shutdown -r now
Ubuntu becomes very, very, very slow! The screen animations becomes so slow that you can see it slideUp-Down instead of the normal animations on the boot screen, login and home screens. What can be the possible issues?