After updated recently, my pc resolution changed. I am using Nvidia driver 390.
Kernel updated to 5.3 recently. But Ubuntu maintainers forgot to update the 390 Nvidia driver to build with that kernel.
The solution is to install a driver from PPA. Run in a terminal:
sudo add-apt-repository ppa:graphics-drivers/ppa sudo apt update sudo apt upgrade
That solved exactly same issue for me.