Hi,

I use Task Manager in a panel placed vertically on the left screen edge of my screen.

Previously I used Kubuntu 16.04 LTS (comes with Plasma 5.5, if I remember correctly). I can push my mouse to the leftmost screen edge and I'm able to switch window easily. It adheres to Fitt's Law.

However, when I switch to using KDE Neon user edition lately (downloaded early April 2018), apparently it doesn't work according to Fitt's Law anymore. Please see screenshots below:
https://imgur.com/tqT9NqO

I have to move back a little to hover on the icon so that I can click and switch to the window:
https://imgur.com/JR6m0X6

The same problem happens for the system tray too - I can't click on the system tray icons at the screen edge, and have to move back in a few pixels to click on them.

Note that this does not affect the Plasma launcher icon (at my top left corner), activity pager below the Plasma launcher icon, and the clock at the bottom left corner. They are working according to Fitt's Law.

Other things I have tried but doesn't help:
- changing system theme
- creating new panel with only task manager widget.
- placing the panel along other screen edges (bottom, top and right screen edges) : it works according to Fitt's Law.

FYI I managed to figure out the cause of my problem. Apparently there is a "Touch screen swipe gestures" being set on the left edge of the screen. Once I remove it, I can now use my mouse and click on the windows on the leftmost edge of the screen.

https://imgur.com/a/is5m1