I have found this xorg conf setting thats brings back the fonts
for plasma-discover and the sddm login screen.
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "DRI" "1"
EndSection
I don’t know why it works, but I do know that it forces
mesa to render via LLVMpipe instead of the i915 driver.
(classic drivers were removed from mesa v22).
By default there is no conf file on a clean lubuntu install.
This makes xorg use the modesetting driver, (which internally
uses the intel driver).
So you will have to create it;
sudo featherpad /usr/share/X11/xorg.conf.d/20-intel.conf
Put in the contents above and save it.
logout
login
You may lose a bit of performance depending on whether you
had a real gpu or not (the mesa native drivers were always
faster than llvmpipe/which is a sort of gpu emulator/).
If things go wrong, CTRL-ALT-F3 and login,
sudo rm /usr/share/X11/xorg.conf.d/20-intel.conf
Then reboot.