I have the same issue but only on my macOS app, on iOS works fine. I have a published app that used to work ok until I upgraded to macOS 14. I created a test project (SwiftUI) with a simple WebView in it and it worked. So, I ended up recreating the entire app project and WebView is working fine. I still don't know what caused this but now it seems to work.

Hi, I had the same problem and also filed a bug report. Since this morning, everything works as expected. Perhaps it was a problem on their backend.