Created attachment 188603 [details] No darkened underlay See attached screenshot. This omission is caused by the use of Qt Controls Dialog, rather than Kirigami Dialog: https://invent.kde.org/plasma/plasma-systemmonitor/-/blob/master/src/table/ReniceDialog.qml?ref_type=heads#L17 Seems like something manual is needed here, or else better styling of the upstream control, or else using Kirigami Dialog instead (though that has worse side margins, so more work would be required than just switching to it).