Logitech trackball ignored by Desktop Configuration GUI

Migrating from 13.2 to Leap 42.2 / KDE Plasma 5, I found that my much-beloved Logitech Trackman Wheel (model # T-BB18) had no pointer acceleration and GUI config had no effect on any settings.

Solution: Uninstall package xf86-input-libinput (along with one dependency.)

Now the GUI actually works (Settings → Configure Desktop). Acceleration can now be adjusted…

(See also: https://forum.manjaro.org/t/unable-to-change-sensitivity-acceleration-logitech-g502/14279/3 )

HTH

I am using Logitech M570.

But I did not have to uninstall anything due to trackball.
But it is true that default KDE setting is OK for me.

Actually, there is no need to remove xf86-input-libinput. If evdev is needed (and assuming xf86-input-evdev is installed) for a particular device, then all that is required is a custom Xorg input config for that device.

I’m interested to learn why I should not want to uninstall xf86-input-libinput. Is some other functionality lost somehow? At this point all I know is that when I uninstalled it, I could suddenly use the mouse-config GUI to actually config my device. It’s working much better now.
…to instead create my own custom Xorg input config for that device… …well, If I start having troubles later, I might get motivated to dig for tutorial info somewhere. Or maybe some kind commenter might toss out a few hints about how to do it… Links or search clues to find examples, discussion… But as of now, …well, the quick fix worked.