Created attachment 164418 [details]
Image showing systemsettings's landing page opened from gui (left) and with kcmshell6 (right)

SUMMARY
Some system settings KCM modules aren't loaded; there is an error loading a qml file. For instance:
```
kf.kcmutils: Error loading QML file qrc:/kcm/kcm_landingpage/main.qml
kf.kcmutils: "    "qrc:/kcm/kcm_landingpage/main.qml:18:1: Type KCM.SimpleKCM unavailable
    KCM.SimpleKCM {
    ^
kf.kcmutils: "    "qrc:/qt/qml/org/kde/kcmutils/SimpleKCM.qml:33:1: Type Kirigami.ScrollablePage unavailable
    Kirigami.ScrollablePage {
    ^
kf.kcmutils: "    "file:///usr/lib/qt6/qml/org/kde/kirigami/ScrollablePage.qml:68:1: Type Kirigami.Page unavailable
    Kirigami.Page {
    ^
kf.kcmutils: "    "file:///usr/lib/qt6/qml/org/kde/kirigami/Page.qml:237:13: Type Kirigami.PageRow unavailable
                property Kirigami.PageRow row
                ^
kf.kcmutils: "    "file:///usr/lib/qt6/qml/org/kde/kirigami/PageRow.qml:180:5: Type OverlayDrawer unavailable
        property OverlayDrawer leftSidebar
        ^
kf.kcmutils: "    "file:///usr/lib/qt6/qml/org/kde/kirigami/OverlayDrawer.qml:22:1: Type KT.OverlayDrawer unavailable
    KT.OverlayDrawer {
    ^
kf.kcmutils: "    "file:///usr/lib/qt6/qml/org/kde/kirigami/templates/OverlayDrawer.qml:120:56: Cannot assign object of type "KTP.IconPropertiesGroup" to property of type "IconPropertiesGroup_QMLTYPE_71*" as the former is neither the same as the latter nor a sub-class of it.
        property KTP.IconPropertiesGroup handleClosedIcon: KTP.IconPropertiesGroup {
``` 
 The error disappears when launching the component from console through kcmshell6 (on the right in image)

Not all modules show this behaviour: Proxy, connection preferences, font manager are shown correctly.

STEPS TO REPRODUCE
1. Open systemsettings
2. 
3. 

OBSERVED RESULT

main widget on the right reports error loading a qml file

EXPECTED RESULT
show settings

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.91.0
KDE Frameworks Version: 5.247.0
Qt Version: 6.7.0
Kernel Version: 6.6.8-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 4 × AMD A8-6500 APU with Radeon(tm) HD Graphics
Memory: 7.7 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 1660 SUPER/PCIe/SSE2