Bug#1144489: Virtual keyboard button in quicksettings is broken

Package: plasma-mobile
Version: 6.7.2-2

Dear Maintainer,
after last upgrades, the quicksettings button to toggle virtual keyboard 
doesn't work anymore. Regardless of pressing it, the button remains 
enabled. System is Mobian testing on op6-enchilada.

Workaroud is to open plasma-settings and disable virtual keyboard from 
there.

I wasn't able to reproduce the issue in up-to-date pmOS, then this seems 
Debian-specific.

I've noticed the following lines in the journal:

ago 14 23:53:47 mobian kwin_wayland_wrapper[2958]: qt.qpa.wayland: 
qtvirtualkeyboard currently is not supported at client-side, use 
QT_IM_MODULES=qtvirtualkeyboard at compositor-side.
ago 14 23:53:58 mobian kwin_wayland_wrapper[2958]: 
qt.virtualkeyboard.hunspell: Hunspell dictionary is missing for "it_IT". 
Search paths QList("/usr/share/qt6/qtvirtualkeyboard/hunspell", 
"/usr/share/hunspell", "/usr/share/myspell/dicts")
ago 15 22:52:50 mobian plasmashell[3063]: Executing 
"plasma-open-settings kcm_mobile_onscreenkeyboard"
ago 15 22:52:52 mobian plasma-settings[26008]: unable to find module 
"kcm_mobile_onscreenkeyboard"

but these are seen in pmOS as well, then likely not the root cause.
The following isn't found in pmOS log and therefore likely the root cause:

ago 14 23:53:53 mobian plasmashell[3063]: 
file:///usr/share/plasma/quicksettings/org.kde.plasma.quicksetting.keyboardtoggle/contents/ui/main.qml:16:5: 
Unable to assign [undefined] to bool

that refers to [1] where the "enabled" status for the quicksettings 
button is defined, that fits with the symptoms. AFAICT looking at the 
code, this relies on plasma-workspace and kwin, but I've no idea how to 
check in which Debian package the issue lies.

Kind regards
Marco

[1] 
https://invent.kde.org/plasma/plasma-mobile/-/blob/v6.7.2/quicksettings/keyboardtoggle/contents/ui/main.qml?ref_type=tags#L16