Sharing an @Published Property over an struct to an extension

Question

I wanted to get my apple watch data on my iPhone in a different view using @StateObject. This worked fine, but recently I wanted to clean up my code with the MVVM (Modelview-ViewModel). So I wrote an extension where all the backend code runs in an extra file.

Now I observed that moving all my code in an extension, comes with some problems. One of them is that I don’t get any data from my WatchManager-Class in my extension. The value never changes!

I know the @Published should update its value if I write new changes to it. The @StateObject is than creating an instance of the watchmanager and watches for changes, this is true for my RecordView, but for any reason deltaDistance2 won’t change if I set a new value the extension.

I don’t know what to do or how to solve this challenge. Can anybody help? Here is my Code:

import SwiftUI

struct RecordView: View {
    // First Try
    //@ObservedObject private var watchManager = WatchManager()
    
    // Second and Third Try
    @StateObject private var watchManager = WatchManager()
    
    @StateObject private var myViewModel = ViewModel(watchManager: WatchManager())
    
    var body: some View {
        HStack {
            // Is needed for user information
            Text("Distance: \(watchManager.deltaDistance)")
        }
        .padding()
        
        HStack {
            Text("Distance2: \(myViewModel.deltaDistance2)")
            Button("set DeltaDistance2") {
                myViewModel.setWithOtherDistance()
            }            
        }
        .padding()
    }
}


extension RecordView {
    @MainActor class ViewModel: ObservableObject {
        // First Try
        //@StateObject private var watchManager2 = WatchManager()
        
        //Second Try
        //@ObservedObject private var watchManager2 = WatchManager()
        
        // Third Try
        private var watchManager: WatchManager
        
        init(watchManager: WatchManager) {
            self.watchManager = watchManager
        }
        
        @Published var deltaDistance2 = 0.0
        func setWithOtherDistance() {
            deltaDistance2 = watchManager.deltaDistance
        }
    }
} 


class WatchManager: ObservableObject {
    @Published var deltaDistance = 0.0
    
    func setDistance() {
        self.deltaDistance = 9.0
    }    
}

At first I tried to only have one @StateObject in my extension, but then no value changed at all.

Second I tried to make an @StateObject in the RecordView and an @ObservableObject in my extension. This didn’t work either.

At last I tried to share the watchManager-instance from the RecordView into the extension. But this didn’t also work.