@Fiz7863: Is this happening with all received calls, or is it just affecting certain contacts? As the problem is occurring on inbound calls, it could potentially be stemming from the caller themselves, given that the issue is resolved when you call them back. If you head to the Samsung Members app > Get Help > Interactive Checks > Mic, and run through the on screen instructions, does this return any errors? Similarly, head over to your phones dial pad and type in *#0283#, then select “Start: RCV_1stMic” and speak into your phone like you’re on a call. Can you hear yourself talk? Once you’ve done that select “Start: SPK_2ndMic”, talk into your phone like you’re talking to someone on speaker phone. Can you hear the playback?
