I can’t think of a good reason why someone would tag a version number rather than releasing it, particularly since the last release was 7 years ago. It would make sense for alpha/beta versions, but why would someone choose to tag a version number rather than releasing it?
I can confirm running manjaro-settings-manager with the QT_QPA_PLATFORMTHEME variable results in correct display of the labels on my system. Would that then point to a recent change in Qt that needs implementing in manjaro-settings-manager???
EDIT: Rechecked recent upgrades, and pango was recently upgraded, which up until now I am unfamiliar with but apparently it is used for text layout for GTK apps. What are the chances of pango being the culprit and breaking my system if I downgrade pango to the previous version in order to identify the issue?
EDIT2: I went down the rabbit hole and learnt some Qt and remembered some C++. I believe the issue is in MsmWindow.cpp line 104. The size is hard coded and thus some recent change in either Breeze or KDE has taken up a couple of extra pixels and pushed the content over the available space and Qt is clever in that it will automatically elide it.
item->setSizeHint( QSize( 135, 100 ) );
A quick fix is to increase the values, but then anyone using a custom UI font may face the same issue.
Calculating the value based on the UI font would be better (but I haven’t read enough yet to know how). Or perhaps setting setTextElideMode(Qt::ElideNone) to force the text to wrap, but I’m not sure if that runs into the same issue if UI font is changed or increased.
Testing if the theme is the culprit displays the text fine, so either Breeze changed recently or the available space for stuff reduced and Breeze takes more space than Fusion.:
QT_STYLE_OVERRIDE=fusion manjaro-settings-manager