Two finger scrolling stopped working suddenly

Solution 1:

I have this same problem
You can restart the touchpad by:
sudo modprobe -r psmouse
Then,
sudo modprobe psmouse
If you have this problem whenever you wake from suspend, then copy this script:

#!/bin/sh

case $1/$2 in
  pre/*)
    echo "Going to $2..."
    # Place your pre suspend commands here, or `exit 0` if no pre suspend action required
    modprobe -r psmouse
    ;;
  post/*)
    echo "Waking up from $2..."
    # Place your post suspend (resume) commands here, or `exit 0` if no post suspend action required
    sleep 2
    modprobe psmouse
    ;;
esac

Now, place it in the /usr/systemd/system-sleep folder, and name it whatever you want.
Now, type sudo chmod +x "whatever you named your script"

Solution 2:

There may be an option in the settings. Check under the touch pad settings, or try reinstalling touchpad drivers.

Solution 3:

Closing the lid to suspend and waking the laptop back up fixed it for me.