Do you experience the same problem with the Icons-Only Task Manager too, or only with the regular Task Manager?

Since a few months/years, Icons-only Task Manager is an alias to Task Manager, see here: https://phabricator.kde.org/source/plasma-desktop/browse/master/applets/icontasks/

I know, but they can still have different behavior. I use a vertical Icons-Only Task Manager (on the left size) and it works fine. That's why I'd like to know if the problem persists with an Icons-Only Task Manager for you.

I have the exact same problem for both. There is exactly one pixel between screen edge and the icon with my setup.

Do you have compositing off? And can you take a screenshot?

OK so apparently, I can’t reproduce this problem on my work computer running the same OS (Arch Linux) (Compositing is on for both). It may have something to do with DPI (92x91 dots per inch at work, 96x96 on my personal computer).

So your personal computer uses the standard 96 DPI in System Settings > Fonts > Force Fonts DPI, and it's broken there, but your work computer uses 92 DPI in System Settings > Fonts > Force Fonts DPI and it does work there?

I didn’t force anything, it’s the values I get when I do `xdpyinfo | grep dots`.

Thanks. Can you provide a screenshot? Is there a visible line where the desktop shows through?

FWIW, for me `xdpyinfo | grep dots` shows 96x96 and it works fine.

OK so:

– I can reproduce the problem with a fresh new panel
– The problem happens when the panel is on the left, not on the right, despite being identical in appearance
– I can’t see the wallpaper on the left
– The problem happens with Plasma themes Breeze Light, Breeze Dark, Air, Oxygen
– I can reproduce it with all the screen resolutions I can use, up to 1366×768
– Size of the panel doesn’t affect the issue
– Compositor being enable or disabled doesn’t affect the issue
– Settings of the widget don’t affect the issue

I can’t see anything else that could alter the behavior or layout of the widget…

Thanks for all the information. Quite an odd issue.

It’s fixed for me since the last KDE Frameworks update (5.49.0).

Well, I have this problem again on another computer (also Arch Linux and DPI: 96x96).

I still have this issue… Is there any way I can investigate that myself? I might be able to edit some QML to see if I can find the issue, if that’s possible.

I noticed quite an odd behavior:

- I set Plasmashell or Latte-dock to the left (respectively right) of the screen
- I put my mouse on the line of pixel to the left (resp. right) edge of the screen, on the task manager
- The Plasmashell/Latte-dock panel appears, putting my cursor one pixel to the right (resp. left)
- If I put my cursor to the left (resp. right) edge again, the panel disappear without animating and reappears with animation, putting again my cursor one pixel to the right (resp. left)

Also, at the left (resp. right) edge of the screen, right-clicking on the task manager (or the systray) doesn’t work, but it works at 1 pixel to the right (resp. left), even for systray who doesn’t react to single click there.

So there is at least three “types” of widgets I can identify:

- Task Manager: 1 pixel line doesn’t work for single and right-click, works otherwise.
- Systray: 1 pixel line doesn’t work for right-click, a few pixel lines doesn’t work for single click (because the click area for those items is so small).
- Menu or clock: clicks works everywhere

For anyone experiencing this, does it go away if you turn off the default KWin touch screen edge at System Settings > Desktop behavior > Touch Screen?

I disabled it and restarted Plasma and I still have this problem.

Can you reboot as well?

Holy shit that’s working! I’m not sure what should be done about it but at least it fixes the problem for me :)

I had a feeling. :)

*** This bug has been marked as a duplicate of bug 387775 ***