Comment 1 for bug 2054246

The lockscreen *should* be disabled by default. As discussed on Matrix, this is directly controlled by the following file:

https://git.launchpad.net/casper/tree/scripts/casper-bottom/34disable_kde_services

So, unless something has changed in how KDE Frameworks gets the lockscreen information, this is definitely the culprit. And regardless of if there was a change in the KDE Frameworks, we now have to identify that change and work around it.