Comment # 1 on bug 954252 from Wolfgang Bauer

Hm, works fine here on 13.2 with the latest packages from KDE:Frameworks5.

Are you sure you used Plasma5's systemsettings5 to change the setting?
As you upgraded from 13.2, you will still have KDE4's systemsettings installed
and might have called that by accident.

To be sure, run "systemsettings5" in a terminal window (Konsole e.g.), and try
to set it again.