Can I fix this big difference between swiftui preview and actual watch widget layout?

Hi,

working on customising my live activity Smart Stack layout for ios18.

A thing that is very frustrating is that I consistently looks different for me in the Xcode preview and on the actual watch.

See attached screenshots below. The sizes are different, and italic doesn't work on the watch, for example.

It makes it time-consuming and unpredictable, so I was wondering if this is a known issue or if I'm doing something wrong, and also can I do anything?

thanks

edit: this is the layout:

var body: some View {
    VStack(alignment: .center, spacing:4) {
        HStack(alignment: .center) {
            IconView(resource: "n-compact-w", bgColor: Color.checkedIn, padding: 2, paddingRight: 6, paddingBottom: 6)
                .frame(maxWidth: 25, maxHeight: 25).aspectRatio(1, contentMode: .fit)
            Text("Checked Out")
                .font(.title3).bold()
        }
        Text(status.loc)
            .font(.headline)
            .multilineTextAlignment(.center)
        Text(FormatUtils.getFormattedDateTime(status.time)).font(.subheadline)
            .multilineTextAlignment(.center).italic()
    }
}