Another reason why I use cifs with systemd-mounts or Smb4K. 
The former, especially, bypasses bugs in KDE.
This reminds me of the other KDE bug in which you must select and apply a setting in order to use another setting, because this “ritual” properly resets the config file behind-the-scenes.[1]
[1] Does Fall Apart effect work in your Kde Plasma? - #13 by winnie