SUMMARY
In a multiple display's setup, application launcher do not remember the display it is set in after powering down and up one of the monitors.


STEPS TO REPRODUCE
1. Create a setup with three monitors. Assign the launcher to the center display.
2. Open few windows and put them around the screen ( not needed surely, just to make the point that they do remember where they are).
3. Power off the first and the third monitor.
4. Power on the monitors again.
5. Launch the  Application Dashboard.

OBSERVED RESULT

Application Launchboard wakes up in the first monitor.

EXPECTED RESULT

Application Launchboard should wake up in the center monitor, which is the one where the launcher sits.
IMPORTANT: Just to be clear... prior to powering down and up the monitors, the launchboard correctly wakes up in the middle monitor, where the launcher is located.


SOFTWARE/OS VERSIONS
Operating System: Kubuntu 23.04
KDE Plasma Version: 5.27.4
KDE Frameworks Version: 5.104.0
Qt Version: 5.15.8
Kernel Version: 6.2.0-27-generic (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-6700K CPU @ 4.00GHz
Memory: 31.3 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 4070/PCIe/SSE2

ADDITIONAL INFORMATION
Windows do magically remember where they were sited once I power up those monitors. Great job! Maybe that is the clue to solve it. Yet I would guess that simply asking everytime what monitor has the launcher sited should solve the problem.