Comment # 12 on bug 1191402 from Mrcuve0

> xdg-desktop-portal-gnome should not be installed or running.

I uninstalled it and rebooted and the problem (which was solved) is back again.

> Is xsettingsd running? 

Yes.

> Is xdg-desktop-portal-kde installed and running?

Yes, Yes. I have "xdg-desktop-portal", "xdg-desktop-portal-kde" and
"xdg-desktop-portal-gtk" installed and running.

> qdbus-qt5 org.kde.kded5 /modules/gtkconfig

method QString org.kde.GtkConfig.gtkTheme()
method void org.kde.GtkConfig.setGtkTheme(QString themeName)
method void org.kde.GtkConfig.showGtkThemePreview(QString themeName)
signal void org.freedesktop.DBus.Properties.PropertiesChanged(QString
interface_name, QVariantMap changed_properties, QStringList
invalidated_properties)
method QDBusVariant org.freedesktop.DBus.Properties.Get(QString interface_name,
QString property_name)
method QVariantMap org.freedesktop.DBus.Properties.GetAll(QString
interface_name)
method void org.freedesktop.DBus.Properties.Set(QString interface_name, QString
property_name, QDBusVariant value)
method QString org.freedesktop.DBus.Introspectable.Introspect()
method QString org.freedesktop.DBus.Peer.GetMachineId()
method void org.freedesktop.DBus.Peer.Ping()

> qdbus-qt5 org.kde.GtkConfig /GtkConfig org.kde.GtkConfig.gtkTheme

Aritim-Light-GTK