Bug 466399

Created attachment 156707 [details]
Output of kscreen-doctor -o, xrandr, as well as a screenshot that shows System Settings and the panel settings dialog

SUMMARY
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I'm using KDE Plasma on my laptop, a ThinkPad T490. When I'm working at my desk, I connect it to two external monitors through a USB-C dock (Anker 565). I want the left monitor to be my primary screen and show my panel, and the right monitor should be secondary. The laptop's internal screen is disabled.

Whenever I boot my system with the dock connected, the system confuses the primary display selection. The panel appears on the secondary screen. In total, three different components on my system seem to have three different opinions about which display is the primary one:

- If I ask xrandr, it says the internal screen is the primary.
- If I ask System Settings, it says the left external display is the primary (this is the desired result).
- If I ask the "Panels and Desktops Management" dialog, it says the right external display is the primary and therefore used to show the panel.

I attach the output of kscreen-doctor -o, xrandr, as well as a screenshot that shows System Settings and the panel settings dialog.

To fix the issue, I have to manually change the primary display in System Settings twice. First, I make my secondary screen primary; second, I make my main monitor primary again. After doing this, xrandr, System Settings and the panel settings all agree on the primary display and the panel moves to the correct screen. However, I have to repeat this process after every boot.

The same behavior appears when I use a Thunderbolt dock (Lenovo DK1841) instead of the USB-C dock. Unfortunately I cannot connect two displays to my laptop without any external adapter, so I cannot test it without one of the docks in between.

I'm using X11. The primary display is correctly identified on Wayland.

Please let me know if I can provide any further information that might be helpful. If you do not consider this a bug in KScreen, I apologize and would be grateful for any advice about where I can raise this issue instead. Thanks!

STEPS TO REPRODUCE
1. Boot the system with external monitors connected to USB-C dock (SDDM displays the login screen on all three screens)
2. Sign in

OBSERVED RESULT
The internal screen is disabled (this is good), but the panel appears on the wrong external screen.

EXPECTED RESULT
The system should correctly remember my primary screen and show the panel on the correct screen.

SOFTWARE/OS VERSIONS
Windows: --
macOS: --
Linux/KDE Plasma: Fedora 37 / Plasma 5.27.1
(available in About System)
KDE Plasma Version: 5.27.1
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION