iOS widget always displaying placeholder on simulator or device

I'm made an very basic iOS Widget Extension with (on iOS 16):

struct TotoView: View 
    var body: some View {
        VStack {
            Text("Toto")
                .font(.headline)
        }
    }
} 

On the SwiftUI Canvas preview, I can see the "Toto" text.

BUT when I select the Widget Target and run in the simulator, I only have the placeholder in place of text. Any idea of why?