With the following Monitor layout:
(Blue numbers added for easier reference)
The very first application window after login, or after closing each and every window, is almost every time placed on Monitor 3.
Expected behavior: Windows open on the Monitor the Application is started on / from (if there is no windows rule for it which is not).
The second and any application Window opened after that follows the expected behavior but the first does not.
tldr:
1: Display (eDP): 2560x1440 @ 240 Hz (as 1706x960) in 17″ [Built-in] *
2: Display (DP): 2560x1440 @ 120 Hz (as 2048x1152) in 27″ [External] [HDR]
3: Display (HDMI): 2560x1440 @ 60 Hz (as 2048x1152) in 27″ [External]
Monitor 1 is my integrated Notebook Monitor and set as Primary display.
Monitor 2 is when “docked” (most of the time) my real main Monitor but I leave Monitor 1 set as Primary to separate my Mobile from my Docked usecase setup.
Monitor 3 is the least used one, has mostly a bunch of systeminfo widgets, clocks for different timezones and such stuff on it. And sometimes other usages.
All three of then have a KDE Taskbar on it, Monitor 3 mostly only for if I run fullscreen stuff on 1 and 2 to easily see if something is behind them.
It does not matter what Application I open first, most times it is the Web-browser or the E-Mail client but even if I open Kate or Konsole or LibreOffice Writer from the Taskbar/Starter on 1 or 2 it opens on 3. That I have to annoyingly drag down to 2 (or 1).
And with “almost every time” I mean in the last one and a half month it not happened maybe three or four times but I could not figure out the condition to trigger the correct/expected behaviour and next time it happened again. I waited this long for reporting this issue because I thought I could catch it but no.
And as a side note: what is even more funny, all windows closing animations go exclusively to the Taskbar on Monitor 3 regardless on which Monitor the Application is closed.
I have no windowsrules, except for some wine games, as I think it makes no sense to force things open for example on Monitor 2 and than take the Notebook with me and not have a Monitor 2.
Operating System: Arch Linux
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.5.0
Qt Version: 6.7.2
Kernel Version: 6.10.10-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 32 × 13th Gen Intel® Core™ i9-13900HX
Memory: 62.5 GiB of RAM
Graphics Processor: Mesa Intel® Graphics
and NVIDIA GeForce RTX 4070 Max-Q / Mobile