Platform and Version
Platform: iOS iOS Version: 17.0+ Development Environment: .NET MAUI (C#, .NET 9) Network Layer: HttpClient with HttpClientHandler
Description of the Problem We are facing an issue where HttpClientHandler.ServerCertificateCustomValidationCallback is not being invoked when the app is in a terminated (kill) state. In normal app lifecycle states (foreground/background), the callback is triggered as expected and allows us to handle server certificate validation (e.g., for certificate pinning or custom validation logic). However, when the app is in a killed state and is relaunched due to a notification action, the callback does not execute. We would like to understand:
Why ServerCertificateCustomValidationCallback is not invoked in this scenario Whether this behavior is expected within iOS networking/runtime constraints Any recommended approach or workaround to ensure certificate validation still occurs when handling notification-triggered flows from a terminated state
Steps to Reproduce
Ensure the app is force-terminated (kill mode) Configure a push notification with category: "INVITE_CATEGORY" Include custom notification action buttons Tap one of the custom actions This triggers app launch and network call using HttpClient
Expected Behavior ServerCertificateCustomValidationCallback should be invoked during the network request initiated after tapping the notification action, allowing custom certificate validation.
