Apple lists bug fixes in the official iOS 11.4.1 change log, but the iOS 11.4.1 update comes with three known bug fixes.
They include a fix for an issue that prevented some users from viewing their last known location of their AirPods in Find my iPhone, improved reliability of syncing mail, contacts, and notes with Exchange accounts, and an unlisted fix. The unlisted fix is for a bug that caused some devices to crash when the the Taiwan emoji was used or when the word "Taiwan" was entered into a text field in apps like Messages, WhatsApp, and Facebook. If that bug fix was impacting your day-to-day use, you should think about installing the iOS 11.4.1 update immediately.
If you skipped iOS 11.4, your iOS 11.4.1 update will be loaded up with additional bug fixes including:
- Fix for an issue where certain character sequences could cause Messages to crash
- Fix for a Messages issue that could cause some messages to appear out of order
- Fix for an issue that could prevent logging in or accessing files on Google Drive, Google Docs and Gmail in Safari
- Fix for an issue that could prevent data syncing in Health
- Fix for an issue that could prevent users from changing what apps can access Health data
- Fix for an issue that could cause an app to appear in an incorrect location on the Home screen
- Fix for an issue where CarPlay audio could become distorted
- Fix for an issue where selecting music from your iPhone could fail when playing music over Bluetooth or when connected to USB on some vehicles
iOS 11.4 included a fix for the well-publicized "Black Dot of Death" iMessage bug that crashes Apple's Messages app with a specific string of characters. iOS 11.4 also fixed a 3D Touch issue affecting devices running iOS 11.3 and iOS 11.3.1 where the feature wouldn't work without waiting a few seconds, or longer, immediately after unlocking an iPhone and a fix for an issue where app icons would start hovering out of place.
If you skipped iOS 11.3.1, you'll get an additional set of fixes with iOS 11.4.1. Apple's iOS 11.3.1 update addressed an issue where touch input was unresponsive on some iPhone 8 and iPhone 8 Plus models because they were repaired using "non-genuine" replacement displays. You'll also get the following fixes from iOS 11.3.1: Keyboards
- Fixes a problem that could cause the capitalization of the first letter of some words by the automatic correction feature.
- Fixes an issue on the iPad Pro that prevented the iPad Smart Keyboard from working after connecting to a captive Wi-Fi hotspot.
- Fixes a problem that could cause undesirable activation of the digital layout on the Thai keyboard in landscape mode.
Accessibility
- Corrects a problem with the incorrect description of the Bluetooth status icon and the Bluetooth icon by VoiceOver.
- Fixes a problem that may prevent the end of call button from appearing in the Phone app when using VoiceOver.
- Fixes an issue preventing access to an app's built-in ranking with VoiceOver.
- Fixes a problem that may cause distorted audio playback when using real-time listening.
General Fixes
- Fixes a problem that may prevent incoming calls from activating the screen.
- Fixes a problem that may prevent or prevent voicemail playback.
- Fixes an issue that prevents opening a web link in Messages.
- Fixes a problem that may prevent users from returning to Mail after previewing an attachment to a message.
- Fixes a problem that could cause the deleted screen to reappear on the locked screen.
- Fixes a problem that can cause the time and notifications to disappear on the locked screen.
- Fixes an issue that prevents parents from using Face ID for approving purchase authorization requests.
- Fixes a problem that could prevent updating of the current weather conditions in Weather.
- Fixes a problem that could prevent the synchronization of contacts with a vehicle directory when connected via Bluetooth.
- Fixes a problem that may prevent an audio app from playing content in a vehicle while it was in the background.
If you skipped earlier versions of iOS 11, your iOS 11.4.1 update will come with a variety of other bug fixes thanks to the versions you skipped. | 
