I have a strange problem with an iPhone SE with iOS version 11.4. The problem is that the microphone does not work, when I switch on the speaker during an active call. By switching off the speaker, everything works again.
As a test, I can record Voice Memos or Video Messages without any problems.
Only when there is an active call and the speaker button is pressed, the person on the other side cannot hear me... It looks like that that the speaker and the microphone uses the same bus and hence kind of unable to multiplex.
Does anyone know the cause and solution of the problem?