iOS13.1 NSURLErrorDomain 467

My app is using a custom WKURLSchemeHandler with WKWebView. It works with Xcode 10 and iOS 12, but I have just complied everything using Xcode 11.1 & the iOS 13.1 SDK. When I run that code on the iOS 13.1 Simulator, and start a web journey, I always get an error returned in

webView(_:didFailProvisionalNavigation:withError:)


Logging it describes the error as:

Error Domain=NSURLErrorDomain Code=467 "(null)" 
    UserInfo={_WKRecoveryAttempterErrorKey=}

I cannot find that error code described anywhere. Does anybody have an idea what this means? This is blocking all of the web journies in my app right now.


Thanks,

Warren