Animation issue when Long-Press is canceled - SwiftUI, iOS 14.5 - animation

Question

I'm still learning and trying to understand the ins and outs of swiftUI. Currently, I focus on understanding gestures and animations and here is an issue that seems unsolvable at my experience level:
The problem:
I experience unexpected behavior if the longPressGesture is canceled, eg. lifting the finger before the minimumDuration of the longPress is exceeded.
The expected result:
In the example above you see me long pressing 2 times and afterward canceling the long-press once. I would expect the red progress bar to scale down again and keep its position centered if the longPress was canceled. But as you can see, the progress bar changes its position.
What is causing this issue and how could it be solved while still using swiftUI and GestureState
Here is the code:
struct DiamondPress: View {
#GestureState var isDetectingLongPress = false
#State var completedLongPress = false
var longPress: some Gesture {
LongPressGesture(minimumDuration: 2)
.updating($isDetectingLongPress) { currentState, gestureState, transaction in
gestureState = currentState
transaction.animation = Animation.linear(duration: 2.0)
}
.onEnded { _ in
self.completedLongPress.toggle()
}
}
var body: some View {
ZStack {
Color.offWhite
RoundedRectangle(cornerRadius: 12, style: .continuous)
.frame(width: 100, height: 100, alignment: .center)
.foregroundColor(.white)
.scaleEffect(completedLongPress ? 2.0 : 1.0)
.gesture(longPress)
.animation(.easeIn(duration: 0.2))
// here is the red progress bar:
Rectangle()
.frame(
width: !isDetectingLongPress ? CGFloat(5) : CGFloat(100),
height: 5, alignment: .center
)
.foregroundColor(.red)
}
.edgesIgnoringSafeArea(.all)
}
}
Thanks a bunch, any help or hint is highly appreciated.