Comment 15 for bug 1760338

Deleting the synaptics driver resolves the issue.
It appears the driver needs to be deleted with the introduction of the libinput driver (now that the synaptics driver has been deprecated).

However this issue/bug occurred as the synaptic driver was not deleted during the upgrade to 18.04 from 16.04 (most likely due the the fact that the config file was not empty - however it would be impossible for it to be empty if it was the driver used in 16.04, prior to the introduction of the libinput driver with the 18.04 upgrade).

Suggestion: For all future upgrades to 18.04, there is the need to ensure the synaptic driver is removed to avoid breaking this functionality and introducing the conflict. If the user decides he/she needs the deprecated synaptics driver, they can always install it after.
This way, Ubuntu 18.04 and beyond would not appear defective in this instance after an upgrade.

Affects: Upgrades to 18.04 and newer.

Conclusion: This bug can be closed when this is fixed in future releases of Ubuntu.

I'm not sure who needs to be communicated about this, can someone please help to see this through to obtain a fix implementation and thus closure? Thanks.