I have an IPhone 8 with IOS 11.1.2. Ever since I've had the phone, which was the first day it was available, the microphones are reversed when I'm on a phone call. More specifically, when I'm holding the phone to my ear, the speaker phone microphone is active. When I remove the phone from my ear, and am speaking on the speaker phone, the microphone that should be active when holding the phone to my ear is engaged. The reason this is serious is because when holding the phone to my ear for an important conversation, you can hear a lot of background noise and much more echo than when I'm speaking on the speaker phone. I've tested this many times, with each new update for IOS 11, and the same problem persists. I have note been able to test this with another IPhone 8, but I do know that users with an IPhone 6 who have upgraded to IOS 11 do not have this same issue.
I would appreciate development looking at this and please solving the issue. Thanks so much.