Lenovo Carbon X1 5th gen trackpad not working

I am trying to install ubuntu in a dual boot setup, in parallel with Win 10. Ubuntu was ok, except that the trackpad did not work. I saw that kubuntu might handle better some hardware. It doesn't work either.

The track pad buttons have no effect whatsoever. The touchpad in itself seems to do something. If I move my finger all around, from time to time, the mouse pointer will move once. But that's pretty much it.

The following post suggests disabling the trackpad in the BIOS: Trackpoint device not available on Lenovo Carbon X1 5th generation This works, I can move the pointer around. However: - clicks don't work (any of them: trackpad, buttons) - now of course it doesn't work any more under Windows. So this is not a solution.

Another post suggests trying:

sudo modprobe -r psmouse
sudo modprobe psmouse

This has no effect.

I have run the following commands, hoping this can help in debugging things:

$ xinput -list
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Logitech K400                             id=9    [slave  pointer  (2)]
⎜   ↳ Logitech M510                             id=10   [slave  pointer  (2)]
⎜   ↳ Logitech USB Keyboard Consumer Control    id=14   [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=17   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Sleep Button                              id=8    [slave  keyboard (3)]
    ↳ Integrated IR Camera: Integrate           id=11   [slave  keyboard (3)]
    ↳ Integrated Camera: Integrated C           id=12   [slave  keyboard (3)]
    ↳ Logitech USB Keyboard                     id=13   [slave  keyboard (3)]
    ↳ Logitech USB Keyboard System Control      id=15   [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=16   [slave  keyboard (3)]
    ↳ ThinkPad Extra Buttons                    id=18   [slave  keyboard (3)]
    ↳ Logitech K400                             id=19   [slave  keyboard (3)]
    ↳ Logitech USB Keyboard Consumer Control    id=20   [slave  keyboard (3)]

I tried a few other things: Changing the grub configuration to use:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i8042.nopnp"

No effect. Also tried to blacklist i2c_hid, no effect.

Any suggestion is appreciated!