My ThinkPad X1 Carbon (7th generation) sometimes has the same problem as this person on Microsoft Answers. Sometimes, after I've been using the computer for a while, the touchpad becomes unresponsive. The cursor won't move immediately when I move my finger on the touchpad. If I keep moving my finger, after a few seconds it will start working normally. Clicking the touchpad will also restore the normal behaviour as long as my finger stays on the touchpad. As soon as I lift my finger off, it will revert to the broken state, and if I put my finger down again it will take a few seconds of continuous input to respond.
Rebooting typically fixes this. The Microsoft Answers post suggests updating the touchpad drivers, but when I open the touchpad in Device Manager, it's using a generic Microsoft driver for which there is no update:
I've discovered that I can also fix the problem by disabling and re-enabling the device from this dialog without a full reboot, so I'm pretty sure it is a driver or firmware bug of some kind. But the Lenovo website doesn't have a touchpad driver for this laptop, and I don't seem to have the UltraNav or PalmCheck settings under Mouse Properties as described in this blog post. I'm also skeptical that the problem has something to do with PalmCheck, as suggested in this Reddit thread from someone who seems to have had the same issue on two different ThinkPads.
I did find some updated firmware for the touchpad, but I apparently already had that installed.
