I have the exact same issue: a MTKView that I want to present in a SwiftUI sheet on macOS 15. This solution does not work for me. The same code works on macOS 14.

For me this issue started to appear when I took down the iOS minimum deployment of my extension to 16.2 instead of 18.0. I fixed it by adding @available(iOS 18.0, *) above all my #Preview: @available(iOS 18.0, *) #Preview("DI compact", as: .dynamicIsland(.compact), using: BackgroundRecordingAttributes.preview) { BackgroundRecordingLiveActivity() } contentStates: { BackgroundRecordingAttributes.ContentState(isAudioOnly: true) BackgroundRecordingAttributes.ContentState(isAudioOnly: false) }