GMSOverlay zIndex issue on tap: Swift iOS Google Maps SDK

Question

I have been trying to implement GMSOverlay on map with overlapping overlays. Setting zIndex did work on displaying overlays on top of each other. But when tapping on top overlay, it is not working as it should. The one behind is overtaking tap.

Can someone help me debug and fix this issue:

Here is the code snippet of overlay implementation:

Overlay Custom class

class OrbisMapOverlayMarker: GMSGroundOverlay {
   var mapPlaceBaseColor: UIColor!
   var mapPlaceId: String!
   var placeCoordinate: CLLocationCoordinate2D!
   var lastCheckinTimeStamp: Date! 
   var radius: CLLocationDistance!
   var fixedRadius: CLLocationDistance! 
   var imageView: UIImageView!
   private var pulseMaxSize: CLLocationDistance = 100
   var increment: CLLocationDistance = 10
   private let maxSizeReference: CLLocationDistance = 100
   private let referenceRadius: CLLocationDistance = 500
   var fixedOpacity: Float = 1
   var isProgressing = true
   var imageUrlName: String = ""
   
   init(bounds: GMSCoordinateBounds, icon: UIImage?, radius: CLLocationDistance) {
       super.init()
       self.imageView = UIImageView()
       self.bounds = bounds
       self.icon = icon
       self.radius = radius
       self.fixedRadius = radius
       pulseMaxSize = (maxSizeReference / referenceRadius) * radius
       increment = (maxSizeReference * 0.1 / referenceRadius) * radius
   }
}

Implementation:

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        let placeSize = orbisPlace.calculatedSize
        let clDistance = CLLocationDistance(placeSize)
        let coordinate = CLLocationCoordinate2D(latitude: orbisPlace.coordinates?.latitude ?? 0, longitude: orbisPlace.coordinates?.longitude ?? 0)
        let topLeftCoordinate = CLHelper.coordinate(from: coordinate, distance: -clDistance)
        let bottomRightCoordinate = CLHelper.coordinate(from: coordinate, distance: clDistance)
        let circleZIndex = Int32(1600 - placeSize)
        
        var color = UIColor(named: AppColors.appBlue.rawValue)
        if let colorHex = orbisPlace.placeDominantGroup?.strokeColorHexString {
            color = UIColor.hexStringToUIColor(hex: colorHex)
        }
        
        let customMarker = OrbisMapOverlayMarker(bounds: GMSCoordinateBounds(coordinate: topLeftCoordinate, coordinate: bottomRightCoordinate), icon: nil, radius: clDistance)
        let mapZoomRadius = mapView.getRadius()
        customMarker.mapPlaceId = orbisPlace.placeKey
        customMarker.position = CLLocationCoordinate2D(latitude: orbisPlace.coordinates?.latitude ?? 0, longitude: orbisPlace.coordinates?.longitude ?? 0)
        let placeOpacity = Float(getPlaceCircleOpacity(forCircle: customMarker, withSize: placeSize, mapRadius: mapZoomRadius))
        if let activeMarker = self.activeGlowOverlay {
            if activeMarker.mapPlaceId == orbisPlace.placeKey {
                customMarker.opacity = 1
                customMarker.fixedOpacity = Float(1)
            }
            else {
                customMarker.opacity = 0.1
                customMarker.fixedOpacity = Float(0.1)
            }
        }
        else {
            customMarker.opacity = placeOpacity
            customMarker.fixedOpacity = Float(placeOpacity)
        }
        customMarker.isTappable = true
        mapMarkers.append(customMarker)
        customMarker.icon = image
        customMarker.zIndex = circleZIndex
        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 1, qos: .userInteractive, flags: .enforceQoS) {
            customMarker.map = mapView
        }
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I have also submitted issue on map sdk repo: https://github.com/googlemaps/maps-sdk-for-ios-samples/issues/118