It seems that the "Pointer threshold" value is set to 4 (when doing a clean install with Ubuntu 18.04.1 as base) but its default is 2 (when clicking the default button). So is it correct to be 4 or not? I did a clean install of Ubuntu 18.04.1, installed updates, restarted Then installed kubunto-desktop, restarted, logged in Opened system settings->input devices->mouse->advanced Had some problems with tabs in konsole as seen in: https://bugs.kde.org/show_bug.cgi?id=398497 and noticed that 2 is the default but it is installed with 4
The .ui and the .cpp both say '2' as the default value. No idea where the '4' comes from, it might be the value in custom configuration files created by the distribution.
Looks like this is an Ubuntu-specific packaging issue. However the UI in question has since changed considerably to properly support the Libinput drivers, so you won't see this issue once you upgrade your Ubuntu version to something more recent.