input devices mouse setting no longer being used.

[Barry Scott]

I have plasma 5.13.2 on Fedora 28.

One of the recent updates broke honoring the mouse settings.
I use left-handed and reversed scroll settings.

Now when I log in I get right-handed and non-reversed scrolling.

If I use the control panel to 

1. change from left to right
2. apply
3. change from right to left

Then I have left-handed and the reversed scrolling.

Is this a known problem? Is there a workaround?

I know that hot plugging a new mouse never works to pick up the settings.
I wonder if this is more of the same?

Does any one know where the mouse settings are persisted on disk?
I'm wondering if they are corrupt in some way.

Barry