SwiftUI @State PW exact same code different result if another optional is added!? :=(

Using Swift
11

How would you describe this bug? Is this a SwiftUI or Swift bug?

My minimum sample code demonstrating the problems:

import SwiftUI


// this is the baseline version and see how thing can change by simply re-arraging init order or initialization of `b`
struct ContentViewCase1: View {
    @State var a: Int?
    @State var b: Optional<Int> // ! b/c this is not initialized,
    
    
    init() {
        a = 1234
        b = 4444
    }
    
    var body: some View {
        VStack {
            Text("a = \(a.map({ $0.formatted() }) ?? "nil")")
            Text("b = \(b.map({ $0.formatted() }) ?? "nil")")
        }
    }
}




// the following two views should be the same as above but is not
// how do you describe this bug to apple for filing a feedback to SwiftUI
// or is this a Swift lang bug?

struct ContentViewCase2: View {
    @State var a: Int?
    @State var b: Optional<Int> // ! b/c this is not initialized,
    
    
    init() {
        b = 4444        // ! just reverse the order and we get another result
        a = 1234
    }
    
    var body: some View {
        VStack {
            Text("a = \(a.map({ $0.formatted() }) ?? "nil")")
            Text("b = \(b.map({ $0.formatted() }) ?? "nil")")
        }
    }
}


struct ContentViewCase3: View {
    @State var a: Int?
    @State var b: Optional<Int> = 9999      // by assigning something here
    
    
    init() {
        a = 1234        // a can no longer be initialized because due to b being init'ed, it get init'ed, unlike case 1
        b = 4444   
    }
    
    var body: some View {
        VStack {
            Text("a = \(a.map({ $0.formatted() }) ?? "nil")")
            Text("b = \(b.map({ $0.formatted() }) ?? "nil")")
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentViewCase1()
        ContentViewCase2()
        ContentViewCase3()
    }
}