Search Toolbar Disappears when Dragging MapView to one side when iPhone Duo is Open

In an app using SwiftUI's NavigationSplitView with UIKit view controllers hosted via UIViewControllerRepresentable in the detail pane, a UIBarButtonItem (system .search) in the hosted view controller's navigationItem disappears visually when the iPhone Duo simulator view is dragged to the right side while the Duo is open, while its tap target remains active in the same location, however when tapped, nothing happens. Dragging back to the center restores the icon. The same button, and the same NavigationSplitView layout, is completely stable under equivalent live window-resizing on Mac Catalyst -- resizing the Catalyst window never reproduces the issue. This seemingly points to the Duo simulator's window/hit-test recomposition during the fold transition rather than an app-level bug. See screenshots. I