We are seeing intermittent WKWebView main-frame navigation failures on iOS 26.4.x.
The failure is reported through:
webView:didFailProvisionalNavigation:withError: The error code is:
NSURLErrorNetworkConnectionLost (-1005) The affected pages are normal HTTPS H5 pages loaded by WKWebView,。
From our client logs, the issue appears during provisional navigation, before the page finishes loading. In many cases, error.userInfo does not contain a useful description, and the log only shows:
did fail provisional navigation, error code: -1005, description: nil We have also observed a high concentration of this error on iOS 26.4.x devices. The failures are intermittent and may recover after a retry, which makes us suspect that the underlying network connection may be lost during request processing or connection reuse.
What we would like to know:
Is there any known issue in iOS 26.4.x / WebKit / CFNetwork that could cause WKWebView provisional navigation to fail with NSURLErrorNetworkConnectionLost (-1005)? Does WKWebView expose any public API or diagnostic mechanism to determine whether the failed request reused an existing TCP/HTTP2 connection? Is there a recommended way to collect lower-level networking diagnostics for WKWebView, such as connection reuse, HTTP/2 stream state, socket close timing, or CFNetwork diagnostics? For main-frame GET navigations that fail with -1005, is a one-time silent retry considered an acceptable mitigation? We can provide timestamps, affected URLs, device OS versions, and client logs if needed.