Created attachment 167379 [details]
Monitor layout

SUMMARY
I have a laptop that's connected to an external monitor. In the Display settings, I have the external stacked above the laptop display so that its laid out vertically (refer to monitor layout in attachments). The external display is marked as primary so that's where my main panel resides. If I disconnect and reconnect the external monitor and then drag a window close to the panel so it unfloats, it causes corruption to appear in the secondary screen. The corruption appears to be a gaussian blurred version of the desktop wallpaper.

STEPS TO REPRODUCE
1. Connect an external monitor to a laptop and stack it above the laptop display in the Display settings
2. Mark external as primary so that panel is displayed on it
3. Disconnect monitor and reconnect
4. Move a window close to the panel so that it unfloats
5. Notice a gaussian blurred bar on the secondary laptop display.

OBSERVED RESULT
A weird blurred bar is shown on the secondary display

EXPECTED RESULT
No weird bar is displayed

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.0.2
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2
Kernel Version: 6.8.1-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 6800U with Radeon Graphics
Memory: 30.7 GiB of RAM
Graphics Processor: AMD Radeon Graphics
Manufacturer: HP
Product Name: HP EliteBook 845 14 inch G9 Notebook PC
System Version: SBKPF