Relevant: http://api.kde.org/4.x-api/plasma-qml-apidocs/BusyIndicator.html (opened twice, one for each theme)
We no longer use lightDM, having moved to SDDM several years ago. As such, this bug report is no longer applicable. Bugs reports for the new SDDM-based login screen should be filed to one of two places: 1. Visual/UI bugs with the login screen UI itself, or feature requests: plasmashell | Theme - Breeze 2. Bugs with the login/user switching process: https://github.com/sddm/sddm/issues