How do I make my Dell XPS 13 Developer Edition touchpad work correctly in 18.04?

Solution 1:

I had the same problem (xps13, update to 18.04) and did the same as in Synaptic touchpad on laptop not working:

sudo modprobe -r psmouse
sudo modprobe psmouse proto=imps

Solution 2:

This fixed my Dell XPS (Cyprus touchpad) issue on Mate Ubuntu 18.04. I saw the issue in both Mate and regular Ubuntu.

sudo apt-get install xserver-xorg-core
sudo apt-get install xserver-xorg-input-synaptics
sudo apt-get install xserver-xorg-input-all

Then reboot