NavigationView animation bug/problem

Using Swift
1

more infos + code on github:
https://github.com/LuegM/animationBug

I am using a Drawer on a Map. (see code below)
As soon as I put a NavigationView over it, an animation appears at the beginning.
Unfortunately I can't get rid of this animation.

.transaction { transaction in
        transaction.disablesAnimations = false
    }

With this command I can remove the animation, but then also the drag animations of the drawer is no longer working.
Does anyone have an idea how I can remove just the animation at the beginning?

struct ContentView: View {

@State var viewAppear = false

var body: some View {
    NavigationView {
        ZStack {            
                MapView()
                MapButtonView()
                DrawerView()
            }
            .navigationBarTitle("")
            .navigationBarBackButtonHidden(true)
            .navigationBarHidden(true)
        }
        .navigationViewStyle(.stack)
    }
}