SwiftUI: Question about SwiftUI's Lifecyle, I think… Object isn't created properly

I'm new to SwiftUI and I have run into an issue I can't explain.

(I know its a lot of text but it would be great if you can help me)

About the project: For the problem three views are important. In View A you can set some values and when you press a button you go to the View C where an object is created with the passed values form View A. In this example every things work, the values are presented in a Text View.
There is also the option to save the values you set in View A and save them to use them later. These objects are saved and when you tap on them in View 0 (View is a view where every saved object is presented)you get to ViewB. There you can go to View C like in View A. Here the values should also be displayed but don't. Only when I press a button in View C do the values appear.

Code:

View A:

Code Block 
NavigationLink(destination: TrainingView(trainingsListVM: übungListVM.transformToTrainingsListVM(daten: daten))){
                    Text("startString")
                        .styleButton()
                } //goes to View C an passes the necessary values

View B:

Code Block 
NavigationLink(destination: TrainingView(trainingsListVM: workout.transformToTrainingsListViewModel())){
                Text("startString")
                    .styleButton()
            }

View C:

Code Block 
struct ViewC: View{
    var trainingsListVM: TrainingsListViewModel
    @ObservedObject var settings = SettingsModel()
    //intervallTimer is the important Object
    @ObservedObject var intervallTimer = IntervallTimer(trainingsListVM: TrainingsListViewModel(daten: Daten()), settings: SettingsModel()) 
   
    var momentaneÜbung: String{ //one of the values I want to display
        if !noExercise{
            return intervallTimer.momentaneÜbung
            
        }else{
            return NSLocalizedString("\(intervallTimer.inTraining ? "trainingString" : "pauseString")", tableName: "Localizable", comment: "")
        }
    }
    
    init(trainingsListVM: TrainingsListViewModel) {
        self.trainingsListVM = trainingsListVM
        intervallTimer = IntervallTimer(trainingsListVM: trainingsListVM, settings: settings) 
     //have to set intervalltimer here again because I need the passes object trainingsListVM which I get from View A or View B
    }
    var body: some View{
         Text(momentaneÜbung) //when I come from View A momentaneÜbung has a value; from View B it is empty on the screen
         .onApperar{
             intervallTimer.setStart()//set the right values
             print(momentaneÜbung) //although it is not shown on the screen, the correct value is sprinted here (when I come from View B)
          }
    }
}

IntervallTimer Object:

Code Block 
 class IntervalTimer: ObervableObject{
     var trainingsListVM: TrainingsListViewModel
var settings: SettingsModel
@Published var trainingsState: [TrainingsState] = []
@Published var übungenListe: Übungen
init(trainingsListVM: TrainingsListViewModel, settings: SettingsModel) {
    self.settings = settings
    übungenListe = Übungen(trainingsListVM: trainingsListVM)
    
    self.trainingsListVM = trainingsListVM
    
    if settings.randomExercise == true{
        self.übungenListe.übungen.shuffle()
    //this init is called when I go to View B but I use it in View C. Shouldn't it only be created when I go to View C
    }
    
}
var momentaneÜbung = ""
...some other variables
func setStart(){
    trainingsState = []
    trainingsState = setTrainingsState(übungenListe: übungenListe)
    
    momentaneÜbung = übungenListe.übungen[0].name //String array with all exercises
    
    trainingsState.removeFirst()
}
}

Things I tested:

• When I call onAppear() in View C an print the value it is printed correctly.

• When I set a breakpoint in the init() of the object I want to create in View C it gets already called when I go to View B

• When I set a breakpoint in the init of intervallTimer and go to View C (coming from View B) this init is called 7 times. In every iteration I print momentaneÜbung. In the first five iterations momentaneÜbung is empty, in the sixth I get the right value but in the last one momentaneÜbung is empty again.

Question: What is the reason for the different behaviour depending on which view I come from?

I hope I have mentioned everything important. I am very happy to receive an answer. Thank you!