voice during call problem with lumia 1520

[WPCentral Question]

hello all
I have aproblem with my lumia 1520 after the last update of wp 8.1 dev.
the callers can't hear my voice and I can hear them good, I find out that this problem only if the wifi is on when I switch it of
the phone working good

 

[FAHMI BASSEM]

Every thing works good on my Lumia 720, your problem is the same of some of Lumia 630 users