Apple iPhone iOS 12 in October 2018 may have upgraded some features regarding iPhone performance (specifically on the iPhone X), though mostly benefiting photo editing and the camera itself, but it has yet to fix issues with iMessage, while also causing issues with the phone display.
Some users have noticed that all iPhone contacts are now organized by Apple ID, which may not seem like much of an inconvenience until users found all iMessages were shared with any member sharing that ID. Messages are showing up as sent from the wrong users, merging message threads, and messages are accidentally being to the wrong users under shared accounts. Apple left this change off their “official” features list for the update in advance, arguably causing their most embarrassing issue for users to date.
This update encourages users to create their own Apple ID to individually purchase Apple Store (apps and iTunes) content instead of sharing content across multiple users.
Many iPhone X owners have also reported that iOS 12 has degraded the quality of their phone’s displays. Poor contrast levels, unsaturated colors, and overexposed black levels are creating multiple side effects for users due to poor calibration. Good photos may look poor when uploaded to an Apple app, social media, or just when viewed on another screen. Some Reddit users recognized this problem existed in iOS 12 beta and posted about it. Nonetheless, Apple didn’t update the issue before sending the software out to millions of users.
Some of these issues have yet to be addressed with iOS 12.1. iPhone X and iPhone XR have noticed a fix in the skin-smoothing issue caused by the wrong base frame for HDR processing in the front camera whenever a selfie was taken. There are 70+ new emojis, alongside an addition of Group FaceTime, Animoji, autofill security codes, and eSIM support that only applies if the phone user’s carrier has started to support the feature.
While Apple has introduced over a handful of new features with their iOS 12.1 upgrade, most of which are only beneficial to iPhone X and iPhone XR users, they have still yet to introduce a fix to the calibration and color display bugs or Apple ID issues. Until then, users can go under General > Accessibility to disable the contrast increase and reduce white point function to give more control over color photo changes. Hope this helps!