Lates CM12.1 nightly --> Wifi turns off on screen off..

Hi everybody,

I recently updated my S4A from latest stock rom to latest CM 12.1 nightly.
Of course I wiped the **** out of it and did a clean install.

Unfortunately, my Wifi keeps turning off, when the screen is off...

Wifi --> Advanced settings --> Keep Wifi alive while standby is set to "always"....

But the phone ignores it and turns Wifi off, anyway.... :/

What can I do?

Thanks in Advance,

McK