I've recently installed Kubuntu 20.04 on an old Thinkpad Helix. It's been mostly working fine, except sometimes the touchpad and trackpoint stop working. Sometimes it happens when the tablet is undocked/redocked, sometimes it happens after resuming from sleep, and sometimes it just happens randomly.
The built in stylus (wacom tablet) and the touchscreen work fine.
The keyboard and USB ports on the keyboard work fine.
So far, the only fix I've found is rebooting the device, which is annoying to do.
I found an answer which said to install
xserver-xorg-input-synaptics and run
synclient TouchpadOff=0 but it didn't work.