The subject describes the situation relatively well. New install of Kubuntu 20.04 on a tower computer with an Asus Prime (Z390-a) motherboard. The process using the ubuntustudio-installer worked fine. I have used the installer before, however I added more groups this time, and have never used the installer on this computer.
After a reboot, the computer has since refused to complete a boot. However, I am able to Ctrl Alt F3 to get a terminal, login as user, run startx and get an X session without problems. I can provide more information if I know which logs to look in at /var/log.
On a hunch, I booted from the generic kernel, which I had no problems with before, and everything works fine. So, as a kludge, I have set Grub2 to boot the generic kernel as default until I can get sorted out what ever is wrong with the low latency kernel...