Xcode 26.3 Simulator renders SwiftUI app only inside a rounded rectangle instead of full screen

Hi everyone,

I’m seeing a strange rendering issue in Xcode 26.3 that seems to affect only the iOS Simulator.

Environment:

• Xcode 26.3
• SwiftUI app
• Reproduces in Simulator only
• Reproduces across multiple simulator device models
• My code is just a minimal example

Expected behavior: The view should fill the entire screen.

Actual behavior: The app content is rendered only inside a centered rounded rectangle/card-like area, with black space around it, as if the app canvas is being clipped incorrectly.

Minimal reproduction:

import SwiftUI

@main struct LayoutShowcaseApp: App { var body: some Scene { WindowGroup { Color.green.ignoresSafeArea() } } }

I also tried wrapping it in a ZStack and using:

• .frame(maxWidth: .infinity, maxHeight: .infinity)
• .background(...)
• .ignoresSafeArea()

but the result is the same.

What I already tried:

• Clean Build Folder
• Switching simulator device models
• Resetting simulator content/settings
• Rebuilding from a fresh minimal SwiftUI project

Since this happens with such a minimal example, it looks more like a Simulator/runtime rendering bug than a SwiftUI layout issue.

Has anyone else seen this on Xcode 26.3? If yes, did you find any workaround?

Thanks.