SUMMARY

This may be related to an earlier bug I filed:

https://bugs.kde.org/show_bug.cgi?id=437929

I can invoke the app launcher from the panel, via touchpad or mouse, but the ability to invoke it via the touchscreen or META Key seems broken. 

Attempts to fix the META key via Plasma Tips:

https://userbase.kde.org/Plasma/Tips#Windows.2FMeta_Key

Have also failed.


STEPS TO REPRODUCE
1. Assign ALT+F1 to App Launcher via Settings and/or invoke the following code:

kwriteconfig5 --file ~/.config/kwinrc --group ModifierOnlyShortcuts --key Meta "org.kde.plasmashell,/PlasmaShell,org.kde.PlasmaShell,activateLauncherMenu"
qdbus org.kde.KWin /KWin reconfigure

2. Press META Key


OBSERVED RESULT

Nothing.

EXPECTED RESULT

Launch App Launcher

SOFTWARE/OS VERSIONS

System:    Host: NEON Kernel: 5.12.9-surface x86_64 bits: 64 Desktop: KDE Plasma 5.22.0 
           Distro: KDE neon 20.04 5.22 
Machine:   Type: Laptop System: Microsoft product: Surface Go v: 1 

ADDITIONAL INFORMATION