PLATFORM AND VERSION iOS Development environment: Xcode 16.2, macOS 15.3.2 Run-time configuration: iOS 15-18 This happens in iOS, and leads to to the hybrid home page showing users as wrongly unauthenticated, since the at cookie is missing. For context, we have a JWT token that is stored in the Keychain, and on app launch, before any WKWebViews are created, we synchronize this to the WKWebsiteDataStore as an at cookie. We have analytics instrumentation on our websitef to show that WKWebView randomly refuses to send out any cookies. – The following is a snippet from an explanation to the WebKit Slack: We are having an issue on iOS, in which WKWebView loads pages (and even subsequent reloads) without any cookies, even though we have stored cookies in WKWebsiteDataStore.default() before hand right after application launch and becoming a key window. We reference this object, store it as a singleton, (as well as a process pool), and then all webview configurations are i