Xcode – @Published String Variable Not Updating View

My @Published string variable in Observableobejct does not update the Text somehow.

Exact same codes works in different view, but I can’t figure out why this isn’t working in this view.

When I searched Google all I figured out was about checking the initialization of observableobject, setting didSet to variable, but all of them did not work and I just reverted back.

The below is the code that does NOT update the view when string changes in viewdidappear().

struct StorageUpgradeView: View {
    @ObservedObject private var storagevm = StorageVM()

    @Environment(.presentationMode) var presentationMode

    var body: some View {
        ZStack {
            VStack {
                ZStack(alignment: .center) {
                    HStack {
                        Button(action: {
                            presentationMode.wrappedValue.dismiss()
                        }, label: {
                            Image("Image_arrowleft")
                                .resizable()
                                .frame(width: 30, height: 30, alignment: .leading)
                        })
                    
                        Spacer()
                    }
                
                    Text("Storage Upgrade".localized)
                        .font(.system(size: 24))
                }
                .padding()
            
                Text(storagevm.month_price)
            
                Text("(storagevm.halfyear_price)")
            
                Spacer()
            }
        }
        .onAppear(perform: {
            storagevm.viewdidappear()
        })
    
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .foregroundColor(Color("Theme_OnSurface"))
        .background(Color("Theme_Surface").ignoresSafeArea())
    }
}

class StorageVM: ObservableObject {
    @Published var month_price = "plpl"
    @Published var halfyear_price: String

    init() {
        halfyear_price = "asdf"
    }

    func viewdidappear() {
        month_price = "BlahBlah"
        halfyear_price = "were"
    }
}

But view prints just well when I switch the view by changing tabs. What is the problem here? I couldn’t figure out after two days of googling and banging my head.