I changed SDDM background, I tried to revert to default background by clicking "Defauls" button and notthing happened. Operating System: Arch Linux KDE Plasma Version: 5.14.90 KDE Frameworks Version: 5.54.0 Qt Version: 5.12.0
Can confirm.
Same on 5.15.2. Along Bug 403366 it seems to affect all the options on sddm_kcm.
Git commit 5bbbe08748e0b1ecf48ea4af35b96fa23ccd0a0c by David Redondo. Committed on 11/01/2021 at 12:42. Pushed by ngraham into branch 'master'. Port to ManagedConfigModule The settings are now read via KConfigXT, with a trick to follow the config scheme of SDDM. One KConfig object is used to read the defaults and another one to read the actual config values, see SddmSettingsBase.h for details. The UI is now entirely in Qml and follows the GridviewKCM style. The preview pane has been moved into a Dialog. The "Advanced" has been moved into a page called "Behavior" and the sync options live now in a OverlaySheet accessible from the main page as does the background configuration. Related: bug 407689, bug 411004, bug 411504, bug 419327, bug 424639 M +2 -0 CMakeLists.txt M +10 -16 src/CMakeLists.txt D +0 -294 src/advancedconfig.cpp D +0 -63 src/advancedconfig.h D +0 -97 src/configwidgets/selectimagebutton.cpp D +0 -50 src/configwidgets/selectimagebutton.h A +196 -0 src/package/contents/ui/Advanced.qml [License: GPL] A +98 -0 src/package/contents/ui/DetailsDialog.qml [License: GPL (v2+)] A +211 -0 src/package/contents/ui/main.qml [License: GPL] A +16 -0 src/package/metadata.desktop D +0 -147 src/qml/main.qml A +42 -0 src/sddmdata.cpp [License: GPL] A +33 -0 src/sddmdata.h [License: GPL] M +247 -57 src/sddmkcm.cpp M +22 -12 src/sddmkcm.h A +39 -0 src/sddmsettings.kcfg A +8 -0 src/sddmsettings.kcfgc A +81 -0 src/sddmsettingsbase.cpp [License: GPL] A +51 -0 src/sddmsettingsbase.h [License: GPL] D +0 -237 src/themeconfig.cpp D +0 -63 src/themeconfig.h M +9 -0 src/thememetadata.cpp M +1 -0 src/thememetadata.h D +0 -155 src/themesdelegate.cpp D +0 -47 src/themesdelegate.h M +80 -2 src/themesmodel.cpp M +16 -3 src/themesmodel.h D +0 -356 src/ui/advancedconfig.ui D +0 -223 src/ui/themeconfig.ui M +5 -4 src/usersmodel.cpp M +4 -2 src/usersmodel.h https://invent.kde.org/plasma/sddm-kcm/commit/5bbbe08748e0b1ecf48ea4af35b96fa23ccd0a0c