Bug 450446 - Multi-monitor setup messed up on every start.
Summary: Multi-monitor setup messed up on every start.
Status: RESOLVED DUPLICATE of bug 427278
Alias: None
Product: plasmashell
Classification: Plasma
Component: generic-multiscreen (show other bugs)
Version: 5.24.1
Platform: Kubuntu Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
Depends on:
Reported: 2022-02-17 12:06 UTC by Syiad
Modified: 2022-02-23 20:03 UTC (History)
5 users (show)

See Also:
Latest Commit:
Version Fixed In:
syiad.al-duri: Wayland+


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Description Syiad 2022-02-17 12:06:10 UTC
Multi-monitor setup gets messed up on every start.

{Secondary monitor has taskbar,  plasma widgets, etc.; primary screen has default wallpaper only.
Secondary monitor stays dark and cannot be re-activated after de-activation to move taskbar and widgets.}
Cannot switch primary between monitors.

1. Start Wayland session.

Screen setup is different from last saved. Secondary display has set wallpaper, taskbar and widgets. Primary display has only default wallpaper and nothing else.

Primary display cannot be switched between monitors; returns to prior setting when pressing "Apply" after having moved the tick to the other display.

Secondary display can be de-activated to move taskbar, widgets, etc. to primary display. However, secondary display cannot be re-activated afterwards.

Same behaviour as with KDE 5.23.x, i.e. screen setup on startup is the same as last saved. Primary can be switched between displays. Secondary can be de-activated and re-activated.

Linux/KDE Plasma: Kubuntu 21.10, KDE 5.24.1

KDE Plasma Version: 5.24.1 (Problem was also present in 5.23.90 & 5.24)
KDE Frameworks Version: 5.91.0
Qt Version: 5.15.2

Secondary display is to the left of primary.
Secondary display connected as DVI-I-1 via Synaptics DisplayLink driver 5.5 Beta (Problem was also present with 5.4.1)
Secondary display scale 100% (resolution = 2560 x 1440)
Primary display scale 200% (resolution = 3840 x 2160)
Comment 1 Nate Graham 2022-02-17 23:10:50 UTC
Is this on X11 or Wayland?

Are you using the PLASMA_USE_QT_SCALING environment variable?
Comment 2 Syiad 2022-02-18 11:28:30 UTC
This is on Wayland.

"Are you using the PLASMA_USE_QT_SCALING environment variable?"
Not sure. If so, then because it has been set by default. How can I find out and where would I set this?
Comment 3 S. Bryant 2022-02-23 09:25:15 UTC
I'm seeing this behaviour too, with Wayland and Plasma 5.24.1 on openSUSE Leap 15.3.

I'm using a laptop with 2 external screens - both connected via display port connections.  The laptop monitor (also the primary display) is always correct, but the other monitors often lose their settings.  This morning, both external monitors were rotated 90 degrees (only one is physically rotated).  This suggests that the name assignment is inconsistent; there was a similar problem under X11 a couple of years back.

The position and scaling settings are similarly affected - which means that sometimes I log in and the mouse pointer is not only on a screen with no panel and default wallpaper, but that screen is positioned away from the others so it won't let the mouse go from one screen to the other.  If it happens to match the right name to the monitor, all of these are correct (position, scaling, wallpaper, panel).

This issue may be vaguely related to #385135 - the same fix seems to help: remove the whole `[ScreenConnectors]` section from `~/.config/plasmashellrc` and restart plasma.
Comment 4 Nate Graham 2022-02-23 20:03:01 UTC

*** This bug has been marked as a duplicate of bug 427278 ***