I recently bought an HP 14-an013nr, which was released within the last two months. It has an Elantech touchpad that does not seem to work. That is, motions with my finger do not result in corresponding motions of the pointer. Sometimes the pointer moves in a different direction. Most of the times the pointer is stationary.
I would suggest trying the libinput driver. It's much newer than evdev and synaptics and fixed some issues I had with the Elan touchpad on the computer I use. It also supports most of the hardware of other drivers supported, including some graphics tablets. Instructions:
Install the package xserver-xorg-input-libinput
sudo apt install xserver-xorg-input-libinput
sudo apt remove xserver-xorg-input-evdev
sudo apt remove xserver-xorg-input-synaptics
Reboot and see if things work better.