Created attachment 145523 [details]
Notification popup showing up at wrong position

SUMMARY
I have an external screen (2560x1600) connected to a laptop, which has an internal screen (1920x1080) but its lid is closed. The panel (menu+taskbar+tray) is on the left side of the screen, and the notification position should be near the tray applet, which is on the bottom left.

It works without problem at first, but after turning off and on the external screen, the notification popup moves to a weird position (see the attached image).

The problem is more obvious if the popup position is set to bottom right - it appears near the center of the screen afterwards.

xrandr output:
> Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 16384 x 16384
> eDP-1 connected (normal left inverted right x axis y axis)
>    1920x1080     60.04 +  59.93
> (... other modelines)
> HDMI-1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 596mm x 335mm
>    2560x1440     59.95 +  74.93*
> (... other modelines)

STEPS TO REPRODUCE
1. notify-send something
2. turn the external screen off and on 
3. notify-send something again

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.23.90
KDE Frameworks Version: 5.90.0
Qt Version: 5.15.2
Kernel Version: 5.15.10-zen1-1-zen (64-bit)
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 4800H with Radeon Graphics
Memory: 29.8 GiB of RAM
Graphics Processor: AMD RENOIR