Rollback after sudo apt update & upgrade with Terminal.

So What You gonna need is TTY window or any terminal.

 1)Step - SHOWING ALL THE PACKAGES THAT'S BEEN RECENTLY UPDATED:

  cat /var/log/apt/history.log | grep "\ install\ " | more



  Tip:"| more " for beginning of actions. Press "enter" to move down to last package


 Tip:Once You find the application name You want to downgrade PRESS CRTL-Z


 Step 2) SHOWING ALL THE PACKAGE VERSIONS

  sudo apt-cache showpkg package-name  | more

apt policy chromium-browser 

would work as well




 Tip: "| more " for beginning of all versions. Press "enter" to move down to needed package version.

 Tip:Once You find the application version You want to put on (DOWNGRADE TO) PRESS CRTL-Z

 Step 3) DOWNGRADE TO SELECTED VERSION

  sudo apt-get install packagename=version

 or for example

  sudo apt-get install firefox=59.0.2+build1-0ubuntu1


 AND THAT'S IT, IT SHOULD DOWNGRADE THE ONE PACKAGE YOU SELECTED AND ALL THE OTHER COMPONENTS THAT ARE DEPENDENT ON IT. https://www.linuxuprising.com/2019/02/how-to-downgrade-packages-to-specific.html