I tried to change the "Look And Feel" from Breeze to F24 by opening systemsettings5 from Konsole. Could this be a clue?
"kcm_lookandfeel" "The shared library was not found." Plugin search paths are ("/usr/lib/qt5/plugins", "/usr/bin") The environment variable QT_PLUGIN_PATH might be not correctly set Trying to use rootObject before initialization is completed, whilst using setInitializationDelayed. Forcing completion