Mysterious Behavior of EditButton/EditMode

The behavior of EditButton/EditMode is killing me.

I have a model updating in the background and fetching data from a server every 15 seconds. Several Views are dependent on the updating result.

And now I want to stop auto-updating when the edit mode is active.

So I have code like this:

@Environment(\.editMode) var editMode
 var body: some View { 
    SomeView{
    // somewhere in the view hierarchy there is an EditButton
    }
    .onChange(of: editMode!.wrappedValue){
      if $0.isEditing {
        model.stopAutoUpdate()
      } else {
        model.startAutoUpdate()
      }
    }

And here come the weird things:

1. Every time the model updates, the onChange part gets called.
2. When I tap the edit/done button, nothing gets called even though the List items have the right performance.

I am completely no idea why it behaves like that. Someone please help me.