We’ve encountered significant differences in our VoIP app’s workflow between iOS 17 and iOS 18, particularly on devices with Dynamic Island. Our app functioned as expected in iOS 17 and even iOS 18 on devices without Dynamic Island, but with the public release of iOS 18 on Dynamic Island-supported iPhones, we’re receiving a lot of feedback from users reporting confusing behavior during both incoming and outgoing calls.
Here’s a breakdown of the issue:
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In iOS 17 and iOS 18 (on non-Dynamic Island models), when our app initiates a second call, the app remains in the foreground, allowing the user to see both calls within our UI. Users can manage their calls, swap between them, and even merge them, all without leaving the app. If the user switches to the CallKit controller via the app switcher, it reflects the state of the calls in our app, which has worked well for our users.
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However, on iOS 18 devices with Dynamic Island, adding a second call now backgrounds our app and brings the CallKit controller UI to the foreground. This causes confusion, as users lose context of managing multiple calls within our app. Though users can switch back to our app manually, this extra step disrupts their workflow, especially when handling multiple active calls. This change doesn't occur on iOS 18 devices without Dynamic Island.
Additionally, during an active call, if an incoming call arrives, the Dynamic Island notification takes over, and the app UI is again backgrounded in favor of the CallKit controller screen. Even when declining the incoming call from the notification, the user remains in the CallKit controller UI, requiring another step to return to our app using the app switcher or the "app" button in CallKit.
This inconsistent behavior makes call management unnecessarily complex for our users, who need a streamlined experience, especially since our app is used in healthcare communications that is often critical in nature.
Is there any documentation on changes to CallKit behavior specific to Dynamic Island devices in iOS 18? We’d appreciate any guidance on designing a VoIP experience that doesn’t involve these disruptive view switches, particularly for Dynamic Island-supported iPhones.
Thank you for your help!