It appears to work fine in iOS simulator, but on a physical iPhone 7P (iOS 12.2) there is nothing but a permanent white screen (the status bar is present) after the launch image. Our UI is 100% comprised of a few WebViews each taking up different portions of the screen. The WebViews were originally created in a xib file (pre-existence of constraint system), and I edited the .xib to change from UIWebView to WKWebView in a way that does not change any layout or constraints.
Unfortunately, the code base is too massive (and proprietary) to post a sample that would reproduce it, and I have failed to create a standalone Xamarin.iOS app that is able to reproduce it, but sure have tried.
Is there anything special you need to do to get WKWebView to display properly, that wasn't required for UIWebView?