Display settings fail: Panels on wrong screen or dissappearing

[MannMitHut]

Hi together!

When switching the primary screen in the display settings the panels (or just the one panel) often (but not always) appear on the wrong sceen, meaning for the standard panel the other screen than which is selected as primary. Even worse, if one screen gets deactivated in the display settings often the panel disappears completely. (This leads to the assumption that, then again, the panel moves to the wrong screen, in this case meaning the deactivated one.)

When applying changes often the panel flickers once oder a few times back and forth between the two screens as if there were things fighting against each other. Also, after making switches in the display settings things like the kde menu or some dropdown menus appear on the other screen (and then, of course, disconnected from their actual position).

It’s a general problem in Kubuntu 16.04. I’ve tried on different machines, even with different graphic drivers.

This issue might or might not be related to https://blog.martin-graesslin.com/bl...y-of-plasma-5/ (see "Multi screen woes" there). So it could be a problem with Qt, actually?

Anyway, is there a solution for that? Thanks for help!

[tomwitt]

I'm having this same problem. At the office, I have an external monitor attached to the left of my laptop. At home, I attach to an external monitor to the right of the laptop. Inevitably, the panel goes to the wrong screen. And setting the primary display using the Display Configuration is hit or miss as to whether the panel actually moves to the correct screen.

[MannMitHut]

Exactly the same sympthoms! Thanks for sharing. As I said, this is a general issue in Kubuntu 16.04 and has nothing to do with ones specific setup, and not with ones hardware in particular. Hope this gets adressed and fixed! (Sad that such bugs make it into an LTS which can, as it’s the case for me, make such a great distribution in fact unusable.)

Edit: It’s not even specific for Kubuntu. I’ve just tried under a (freshly updated) Manjaro – same thing.

[sithlord48]

looks like the bug is reported here https://bugs.kde.org/show_bug.cgi?id=346961
and has a work around by making the kscreen config read only. (setting for kscreen are in ~/.local/share/kscreen/<file>)\
this has worked for me on the one machine i tried it on .

[MannMitHut]

@sithlord48: No, we are talking about something different here.

[tomwitt]

My work around has been to acknowledge that the screen setup is borked (even using command line xrandr with switches doesn't work). Instead, I created a new panel, aligned it to the right edge of the screen with option autohide enabled. When my screen setup is working I have two panels (one invisible) but when screen setup isn't working (like in every friggin' conference room meeting I attend), I can use the right edged control panel. From what I've read this is a QT issue; but it could be plasma coders finger pointing at QT coders finger pointing back.

[MannMitHut]

There is hope: https://forum.kde.org/viewtopic.php?f=289&t=132166

(Next question will be: As soon as a patch comes out, will it make it into the Ubuntu-Updates …?)