SUMMARY
Using the "Search" button's functionality after adding the global menu for the first time, plasmashell got hanged, with ~10.2 GB total RAM usage (increased over the period while unresponsive).

Used it with Konsole (konsole 25.08.3) in focus.

STEPS TO REPRODUCE - Not sure if reproducible
1. Add Global Menu to Default Panel using "Add or Manage Widgets" (for the first time??)
2. Open a Konsole window
3. Click the search button in the Global Menu and type some stuff in the search bar
4. Wait
5. systemctl --user restart plasma-plasmashell

OBSERVED RESULT
On step 4:
- All panels hanged and panel-related shortcuts stopped working
- The popped-up search bar stayed visible
- Clicks on the 'icons and text task manager' were unresponsive
- According to Plasma System Monitor, the RAM usage of plasmashell gradually increased upto ~10.2 GB. Swap usage was still at 0
- Alt+Tab was working, but without the overlay
- mouse cursor was working
- the konsole window, for which the global menu had opened, was responding properly

EXPECTED RESULT
- plasmashell does not become unresponsive
- plasmashell does not start using high amount of memory
- search results come up

SOFTWARE/OS VERSIONS
Operating System: EndeavourOS 
KDE Plasma Version: 6.5.2
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.17.7-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800X 8-Core Processor
Memory: 64 GiB of RAM (62.7 GiB usable)
Graphics Processor: AMD Radeon RX 7600 

ADDITIONAL INFORMATION

Not sure exactly at what point, it started hanging (I forgot to look at the clock), but it happened somewhere in between the logged timestamps.
❯ journalctl -b -t plasmashell -t systemd
Nov 14 19:00:30 a-hostname-here plasmashell[1525]: Could not find required file "mainscript" for package "/usr/share/plasma/plasmoids/org.kde.plasma.kickerdash/" should be QList("ui/main.qml")
Nov 14 19:00:31 a-hostname-here plasmashell[1525]: Could not find required file "mainscript" for package "/usr/share/plasma/plasmoids/org.kde.plasma.kickerdash/" should be QList("ui/main.qml")
Nov 14 19:00:31 a-hostname-here plasmashell[1525]: Could not find required file "mainscript" for package "/usr/share/plasma/plasmoids/org.kde.plasma.kickerdash/" should be QList("ui/main.qml")
Nov 14 19:01:34 a-hostname-here plasmashell[1525]: This plugin does not support setting window opacity
Nov 14 19:01:35 a-hostname-here plasmashell[1525]: This plugin does not support setting window opacity
Nov 14 19:01:39 a-hostname-here plasmashell[1525]: This plugin does not support setting window opacity
Nov 14 19:01:41 a-hostname-here plasmashell[1525]: This plugin does not support setting window opacity
Nov 14 19:02:14 a-hostname-here plasmashell[1525]: file:///usr/share/plasma/plasmoids/org.kde.plasma.appmenu/contents/ui/configGeneral.qml:14:1: QML SimpleKCM: Created graphical object was not placed in the graphics scene.
Nov 14 19:02:14 a-hostname-here plasmashell[1525]: file:///usr/share/plasma/plasmoids/org.kde.plasma.appmenu/contents/ui/configGeneral.qml: Setting initial properties failed: SimpleKCM does not have a property called cfg_compactViewDefa>
Nov 14 19:02:26 a-hostname-here plasmashell[1525]: location should be set before showing popup window
Nov 14 19:02:46 a-hostname-here plasmashell[1525]: QQuickVelocityCalculator: a call to stopMeasuring() must be preceded by a call to startMeasuring()
Nov 14 19:03:05 a-hostname-here plasmashell[1525]: Could not find required file "mainscript" for package "/usr/share/plasma/plasmoids/org.kde.plasma.kickerdash/" should be QList("ui/main.qml")
Nov 14 19:03:05 a-hostname-here plasmashell[1525]: Could not find required file "mainscript" for package "/usr/share/plasma/plasmoids/org.kde.plasma.kickerdash/" should be QList("ui/main.qml")
Nov 14 19:03:05 a-hostname-here plasmashell[1525]: Could not find required file "mainscript" for package "/usr/share/plasma/plasmoids/org.kde.plasma.kickerdash/" should be QList("ui/main.qml")
Nov 14 19:03:09 a-hostname-here plasmashell[1525]: This plugin does not support setting window opacity
Nov 14 19:03:11 a-hostname-here plasmashell[1525]: This plugin does not support setting window opacity
Nov 14 19:08:28 a-hostname-here systemd[1124]: Stopping KDE Plasma Workspace...
Nov 14 19:09:08 a-hostname-here systemd[1124]: plasma-plasmashell.service: State 'stop-sigterm' timed out. Killing.
Nov 14 19:09:08 a-hostname-here systemd[1124]: plasma-plasmashell.service: Killing process 1525 (plasmashell) with signal SIGKILL.
Nov 14 19:09:09 a-hostname-here systemd[1124]: plasma-plasmashell.service: Main process exited, code=killed, status=9/KILL
Nov 14 19:09:09 a-hostname-here systemd[1124]: plasma-plasmashell.service: Failed with result 'timeout'.
Nov 14 19:09:09 a-hostname-here systemd[1124]: Stopped KDE Plasma Workspace.
Nov 14 19:09:09 a-hostname-here systemd[1124]: plasma-plasmashell.service: Consumed 17min 23.096s CPU time, 10.5G memory peak.
Nov 14 19:09:09 a-hostname-here systemd[1124]: Starting KDE Plasma Workspace...
Nov 14 19:09:09 a-hostname-here systemd[1124]: Started KDE Plasma Workspace.
Nov 14 19:09:11 a-hostname-here plasmashell[611304]: Applet preload policy set to 1