That bug is closed without a fix though, because 5.18 is unmaintained. However, there's another upstream bug about similar issue in: https://bugs.kde.org/show_bug.cgi?id=449857
WORKAROUND / FIX
1. sudo nano -w /usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/lockscreen/LockScreenUi.qml
2. Comment out "enabled: visible" on line 234
I also have this same problem with Ubuntu 20.04.4 and plasma-workspace 5.18.8-0ubuntu0.1.
I think this is caused by the following upstream bug: /bugs.kde. org/show_ bug.cgi? id=439604
https:/
That bug is closed without a fix though, because 5.18 is unmaintained. However, there's another upstream bug about similar issue in: /bugs.kde. org/show_ bug.cgi? id=449857
https:/
WORKAROUND / FIX
1. sudo nano -w /usr/share/ plasma/ look-and- feel/org. kde.breeze. desktop/ contents/ lockscreen/ LockScreenUi. qml
2. Comment out "enabled: visible" on line 234