var body: some Scene { WindowGroup { ContentView() .frame(minWidth: 720, maxWidth: 1280, minHeight: 720, maxHeight: 1700) } .defaultSize(CGSize(width: 1280, height: 720)) .windowResizability(.contentSize) Will assign a default size. You can also limit the resize range with .frame(minWidth, maxWidth ...)

Now, with VisionOS 1.1 RC2, the problem seems to be resolved.

A check on iPadOS18.2 Beta reveals that the issue is iPadOS related and seems to be fixed in iPadOS18.2.