Running KDE neon LTS User Edition 5.12 on a ThinkPad T450 (which has a touchpad and TrackPoint pointing device). I never use the trackpad so wish to disable it. In settings -> Input Devices -> Touchpad -> Enable/Disable Touchpad, I have ticked "Disable touchpad when mouse is plugged in" and removed all the ignore devices (including the "TPPS/2 IBM TrackPoint"). This works, disabling the touchpad. However if I suspend the laptop and wake it up again, the touchpad gets re-enabled. It seems to be impossible to re-disable the touchpad unless I logout or reboot.
Same here, openSUSE Leap 42.3, latest (5.12) RPMs. There is a workaround: unplug the mouse and plug it back in. But that's a nuisance, since I have a wireless mouse with a tiny USB receiver that I like to just leave plugged in.
This looks to be fixed after doing whatever updates I had pending! Thank you!