I had the same issue... If its a cm11 ROM, its prob the kernal. Use a kernal prior to the cm11.
I'm using spirit ROM 1.1 , had that issue, flashed BMS kernal from the 7-25 or 7-27 date and I'm all good. Just my 2 cent. May work for you also.
I heard its something g to do with the data or WiFi connection. And all ROMs or kernals will be fix soon.
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