Ubuntu 20.04 Text splitting and screen flickering
Solution 1:
I had the exact same condition and I was able to fix it by removing the 3rd party AMD Radeon drivers I had previously installed (and had been working fine up until this morning when I did a SW package upgrade & rebooted). I ran the following commands and rebooted. Now my display is back to normal:
sudo apt install ppa-purge
sudo ppa-purge ppa:oibaf/graphics-drivers