Currently on Xcode 15.4 in a SwiftUI App when you attach a UIView to the rootViewControllers view, which contains a WKWebView, the view will display and allow interaction to it (i.e opening new pages/pressing buttons). However in Xcode 16 beta 4 this is no longer the case. The view will still appear but will no longer be interactive. This happens only on iOS 18 Beta (1-7) and iOS 18.1 Beta.
iOS 18 Beta Bug - SwiftUI/WebKit
You should probably raise this as a bug in the usual way. It won't really get progressed if it's only posted in these Developer Forums.
You need to raise each issue you find separately at https://feedbackassistant.apple.com/ You can post the FB numbers here if you want, so that others can link to them.