Error while accessing core data inside Mapview SwiftUI

Question

I have MapView working for a single Marker. I want to access core data entity and based on the number of items it consists of, I want to create corresponding number of Markers. So inside MapView I defined Core data fetch like this:

@FetchRequest(
        sortDescriptors: [NSSortDescriptor(keyPath: \LocationPublic.uniqueId, ascending: true)],
        animation: .default)
    private var locationPublicItems: FetchedResults<LocationPublic>

Inside MapView, while iterating over the coredata entity locationPublicItems and try to access each item I get error: on the code line (show in detail below):

for detail in self.locationPublicItems {
                let latitudeStr:String = String.localizedStringWithFormat("%.15f", , detail.latitude)
....

Error:

"Accessing StateObject's object without being installed on a View. This will create a new instance each time."

CODE:

struct ProfileMapView: View {
@Environment(\.managedObjectContext) private var viewContext
@Environment(\.dismiss) var dismiss
@State var tracking:MapUserTrackingMode = .follow
@Environment(\.presentationMode) var presentationMode


var body: some View {
    TabView {
        NavigationView {
            ZStack {
                VStack (alignment: .leading){
                    MapView()
                        .ignoresSafeArea()
                }
            }
            //.edgesIgnoringSafeArea(.all)
            
            .safeAreaInset(edge: .bottom) {
                Color.clear
                    .frame(height: 0)
                    .background(.white)
            }
            
            .toolbar {
                ToolbarItem(placement: .principal) { // <3>
                    VStack {
                        Text("Profiles").font(.headline)
                    }
                }
                ToolbarItem(placement: .navigationBarLeading) {
                    Button(action: {  presentationMode.wrappedValue.dismiss() }, label: {
                        HStack(spacing: 2) {
                            Image(systemName: "chevron.backward")
                                .foregroundColor(.black)
                            
                            Button("Back", action: {
                                self.presentationMode.wrappedValue.dismiss()
                            } )
                            .foregroundColor(.blue)
                        }
                    })
                }
            }
        }
    }
    
}

struct MapView: UIViewRepresentable {
    @FetchRequest(
        sortDescriptors: [NSSortDescriptor(keyPath: \LocationPublic.uniqueId, ascending: true)],
        animation: .default)
    private var locationPublicItems: FetchedResults<LocationPublic>
    
    func makeUIView(context: Context) -> MKMapView {
        let view = MKMapView()
        view.delegate = context.coordinator
        return view
    }
    
    func updateUIView(_ uiView: MKMapView, context: Context) {
        
        uiView.mapType = .mutedStandard
        uiView.addAnnotations(self.myPins)
        
    }
    
    var myPins: [GpsData.MyEndPt] = []
    
    init() {
        myPins = cordToMark()
    }
    
    func cordToMark() -> [GpsData.MyEndPt] {
        var myPins: [GpsData.MyEndPt] = []
        var imgIndex: Int = 1
        let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
        var imageFileURL = documentsURL.appendingPathComponent("upload")
        var fileName:String = String(imgIndex)
        fileName.append("Image.png")
        var image = UIImage(systemName: "face.smiling")
        Image(uiImage: image!)
            .resizable()
            .aspectRatio(contentMode: .fit)
            .clipShape(Circle())
            .scaledToFill()
            .frame(width:48, height: 48)
        
        let data = image!.pngData()
        do {
            try data!.write(to: imageFileURL)
        }
        catch {
            print("error writing image to file")
        }
        for detail in self.locationPublicItems {
            let latitudeStr:String = String.localizedStringWithFormat("%.15f", detail.latitude) // Error here
            let longitudeStr:String = String.localizedStringWithFormat("%.15f", detail.longitude)
            let endPtPin = GpsData.MyEndPt(latitude:  Double(latitudeStr) as! Double, longitude: Double(longitudeStr) as! Double, url: imageFileURL as! NSURL, color: "Blue")
            endPtPin.endPtName =  detail.locationName
            
            myPins.append(endPtPin)
        }
        return myPins
    }
    
    // This calls the delegate
    func makeCoordinator() -> MapViewDelegate{
        let rect = CGRect(x: 0, y: 0, width: 200, height: 100)
        return MapViewDelegate(frame: rect)
    }
    
}
}

Looks like I have not defined the correct syntax for fetching core data entity items inside MapView. Can someone please tell me how to fix this?