Comment 3 for bug 1727130

FWIW This description perfectly describes behaviour is still present on 18.04 in X1C laptops. Specifically my X1 Carbon 5th Gen (fully firmware updated in Windows), fully software updated 18.04, has this behaviour repeatably.
It would appear related to variety of other bugs around touchpad malfunction on sleep awake in the X1C series. the modprobe -r psmouse && modprobe psmouse fix works for me.