Plasma Workspace has an update for the LTS release today which reverts a commit which broke lock screen
plasma-workspace;Plasma/5.18;c4a3a4e5b974fb309a6da61252b2b830d2d90683;plasma-workspace-5.18.7.1.tar.xz;e79f9b9c4837e150ef12b24c0001acab84f0101a8f2be39213ef69e7fea6845d http://embra.edinburghlinux.co.uk/~jr/tmp/pkgdiff_reports/plasma-workspace/5.18.7_to_5.18.7.1/changes_report.html https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/768
