Bên mỹ mà cũng dính chưởng nữa AE ơi. I just got a new AT&T Galaxy S4 from Amazon for my fiance. It shipped with the MF3 firmware. Randomly, she calls out or receives a call and there is no audio in or out. After hanging up, and redialing or re-receiving a second call, everything is fine. It doesn't matter if she was moving or in the same location. I can't seem to reproduce it consistently but it is frequent enough to mention. Is this common with MF3? Not sure if it's software of hardware related.