Software updates have been becoming increasingly notoriously for causing bigger problems than the features they bring to the device. After Microsoft faced the debacle of its April 2018 update for Windows freezing up machines while using Chrome, now Apple users are reporting problems on their iPhones too. According to a report by Macrumors, people using an iPhone 7 and iPhone 7 Plus are complaining of disabled microphones after the iOS 11.3 update. Some users have also reported that the speaker on the phone has also been disabled.
While the exact cause of iOS 11.3 disabling the microphone is not known, Apple has mentioned in the document that some of the affected devices may require repair, indicating that a software issue is causing hardware problems. Those affected can take their iPhones to an Apple authorized service centre, however, it is possible that the service representative may not be aware of this newest development, so be sure to either request an escalation, or just point him to the coverage this bug is getting on the internet.