Device activity report data View is hidding when change the tab

I am working on the device activity report. and fetched data is loading on the chart. I am developing app using TabbarController. when I go to another tab and come back to the chart screen, it disappears.

Here, I am working on a storyboard using Swift language, and device activity reports can be fetched only with SwiftUI. So, the problem is with it? Following the current code.

    @State private var context: DeviceActivityReport.Context = .init(rawValue: "Daily Activity")
    @State private var report: DeviceActivityReport?

    @State private var filter = DeviceActivityFilter(
        segment: .daily(
            during: Calendar.current.dateInterval(
               of: .day, for: .now
            )!
        )
//        users: .all
//        devices: .init([.iPhone, .iPad])
    )
    
    @State var isReload: Bool = false
        
    var body: some View {
        ZStack {
            if isReload {
                LoadingView(title: "Data is loading...")
            } else if let report = report {
                report
            } else {
                DeviceActivityReport(context, filter: filter)
            }
        }

      .onAppear {
            DispatchQueue.main.async {
                report = DeviceActivityReport(context, filter: filter)
            }
        }
}


struct LoadingView: View {
    var title: String = "Please wait..."
    var body: some View {
        HStack {
            ProgressView(title)
                .font(.system(size: 14, weight: .medium))
                .progressViewStyle(.horizontal)
                .tint(Color(.darkGray))
                .padding(8)
        }
        .background(Color(.white))
        .cornerRadius(8)
        .clipped()
    }
}