Created attachment 159374 [details]
Dolphin window on the left screen is only maximized until the top of the bottom panel on the right screen

If display scaling is active on the left monitor, then windows will not correctly maximize if the top of the taskbar on the right monitor is above the bottom of the maximizable area on the left monitor.

STEPS TO REPRODUCE
1. Add bottom panel to the right screen. Make it span the entire width of the monitor.
2. Open Display Configuration in settings
3. Enable display scaling on the left monitor
4. Position the right monitor (or increase the size of the bottom panel on the right monitor) so that the top of the panel on the right monitor is above the top of the panel on the left monitor
5. Try to maximize any window on the left monitor

OBSERVED RESULT
Window maximizes only until the top of the taskbar on the right monitor.

EXPECTED RESULT
Window maximizes until the top of the taskbar on the left monitor.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Manjaro (6.1.30-1-MANJARO)
(available in About System)
KDE Plasma Version: 5.27.4
KDE Frameworks Version: 5.105.0
Qt Version: 5.15.9
Graphics Platform: Wayland

ADDITIONAL INFORMATION
The issue does not seem to appear if the left monitor uses native/100% scaling.
The issue does not seem to appear if the right monitor lacks the bottom panel.
The issue does not seem to appear if the bottom panel on the right monitor is below the maximizable area on the left screen.

There is a possibility that the issue does not appear if there's any sort of a gap between the two monitors. I recall this being the case some time ago, but I haven't been able to get any sort of gap between the two monitors while testing today.