Detect tap on PositionComponent with FixedResolutionViewport

When using a FixedResolutionViewport the tap event on a PositionComponent is relative to the screen size and not to the resized viewport as expected. If I remove FixedResolutionViewport the tap is registered correctly. Am I missing something? What can I do to tap correctly on my Component (Circle)?

This is my code. I'm using flame 1.1.0.

Vector2 calculateVector(
    double x, double y, double fieldW, double fieldH, Vector2 size) {
  var calcY = (y / fieldH) * size.y;
  var calcX = (y / fieldW) * size.x;

  return Vector2(calcX, calcY);
}

class TestGame extends FlameGame with HasTappableComponents, ScaleDetector {
  TestGame();

  @override
  bool debugMode = true;

  late double startZoom;
  static double fieldW = 1080;
  static double fieldH = 1717;

  @override
  backgroundColor() => const Color.fromARGB(255, 65, 129, 77);

  @override
  Future<void> onLoad() async {
    double maxSide = max(size.x, size.y);

    var side = maxSide * (fieldW / fieldH);

    camera.viewport =
        FixedResolutionViewport(Vector2(side, maxSide), clip: false);

    final fieldSprite = await loadSprite('field_checkered.png');
    final field = SpriteComponent(
      sprite: fieldSprite,
      size: Vector2(side, maxSide),
    );

    var ply = Circle(
        position: calculateVector(500, 500, fieldH, fieldH, size),
        size: Vector2(50, 50));

    await add(field);
    await add(ply);
  }
}

class Circle extends PositionComponent with TapCallbacks, HasGameRef<TestGame> {
  var isSelected = false;

  var radius = 0.0;
  var paint = Paint()..color = const Color(0xFF80C080);

  Circle({required position, required size}) {
    super.position = Vector2(
      position.x,
      position.y,
    );
    super.size = size;
    super.positionType = PositionType.viewport;
    radius = size.x / 2;
  }

  @override
  void render(Canvas canvas) {
    gameRef.camera.viewport.apply(canvas);
    canvas.drawCircle(Offset(radius, radius), radius, paint);
    super.render(canvas);
  }

  @override
  void onTapDown(TapDownEvent event) {
    isSelected = !isSelected;

    if (isSelected) {
      paint = Paint()..color = Color.fromARGB(255, 75, 0, 76);
      priority = 2;
    } else {
      paint = Paint()..color = Color.fromARGB(255, 253, 147, 255);
      priority = 1;
    }
  }
}