Since iPadOS 18.4, I also discovered a broken NavigationSplitView. My app uses the NavigationSplitView, and I have the case that the view is a little going down. In iPadOS 18.3, it wasn’t. I also use a floating TabBar for the different views. So I have figured out that if I deactivate the TabBar, it works as before. It is very strange. At moment it is only a design failure., but bothering.