Trackpad stopped working after upgrade

[kencamargo]

Lenovo Ideapad Yoga 11S
Upgrading from 18.04 -> 18.10
After upgrade trackpad stopped working
This workaround partially solves it: https://askubuntu.com/questions/262287/synaptic-touchpad-on-laptop-not-working/262364#262364
BUT:
Trackpad only works as a simple mouse (no two fingers scrolling, trackpad settings are not enabled) and it has to be done every reboot (putting the file in /etc/modprobe.d as in the proposed solution does not work).
I have been searching for a better solution for hours but couldn't find anything else, any help would be much appreciated.
TIA,
K.

[Autodave]

Upgrading from one version to another often causes more problems that can be easily fixed. If you must have the newest and greatest, you may want to do a clean install of 18.10. Keep in mind that you will have to do an other upgrade in 5 months though. I only use the LTS releases and I do clean installs: never upgrade.

[kencamargo]

Hi, actually I simplified the story a bit. The trackpad stopped working after an update still with 18.04. My efforts to solve the problem further muddled things up, so I did a clean 18.10 install, and the problem persists. So that's not really an alternative. But thanks anyway.