Solved by checking for navigationAction.targetFrame to be nil. NavigationType will be "other" when the webview navigates with JS (window.open, window.location.href = ''). Checking for nil will catch JS navigation to new window.

The issue seems to be related to requestTrackingAuthorization which is now required to be called in UIApplicationStateActive, but when the prompt is shown the app goes in inactive state, so the status requestTrackingAuthorization gives back isn't correct. Feels like something for Apple to fix quickly, because timeouts and recursions may fail once they fix this