Mic issue during call waiting after updating to 5.1.1

Hi all,

Last week I updated my Xperia Z1 to 5.1.1 pre-rooted firmware and it was clean installation.

I have a problem with the phone which I noticed yesterday. When I was on a call, I received another call waiting notification. So, I ended the first call and answered the second call, however, the calling party couldn't hear my voice. I can hear them, though.

I thought it was temporary issue, maybe a network issue.

But, the same thing happened again today when switching to a call waiting call.

Any idea what might be issue? :crying:

Thanks.