SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***


STEPS TO REPRODUCE
1. Move the dock to in between the two displays
    - Eg, if your primary monitor is to the left of the secondary monitor, move the panel to the right side of the primary montior
2. Maximize a window (say Firefox) on the laptop/primary monitor
3. Connect a second display
4. Move that window over to the second display and maximize the window
5. Disconnect the monitor

OBSERVED RESULT
The window moves back to the primary display (expected), remains maximized (expected), but the window is maximized below the panel, even when the panel is set to 'Always Visible.'

EXPECTED RESULT
Maximizing the window takes the panel into account, resizing accordingly.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kubuntu 23.10
(available in About System)
KDE Plasma Version: 5.27.0
KDE Frameworks Version: 5.112.0
Qt Version: 5.15.10
Graphics Platform: X11

ADDITIONAL INFORMATION
Minimizing and maximizing the window again does not resolve the issue. You should toggle the panel visibility to update the usable area.