Elemantary OS Touchpad is not working on Lenovo Ideapad 330s.
libinput and synaptics installation an configuration but it did not work.
Did you tried this?
sudo apt install xserver-xorg-input-synaptics
Also you could check the part where you should check if you have two touchpads in the following link:
Don't know if this will help, but have you tried to change the touchpad to basic in the bios. this worked for me on a different os.