I had the same issue after migrating from Kubuntu 14.04 to Kubuntu 18.04 on a XPS L321X. Installing xserver-xorg-input-synaptics fixed it for me.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1763209 Title: Cannot click and drag on trackpad To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unity-greeter/+bug/1763209/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
