I've got a fresh install of Ubuntu Mate 18.10 on an Acer R3 netbook and the touchpad is no longer recognized. It worked in 16.04.
Any ideas on what it could be?
Is there a keyboard shortcut for enabling/disabling the touchpad?
16.04 used the synaptics touchpad driver, while 18.04 uses libinput. You could try installing the synaptics driver:
sudo apt install xserver-xorg-input-synaptics
and reboot to use it.
This did the trick, thanks man.