RealityKit - Measuring entity weird - measured from world origin not by entity

I tap screen and get result hit point. from that point, I want to measure distance to a 3d object placed on ar view.

code is

*for placing 3dobject

 let anchorEntity = AnchorEntity(anchor: anchor)
anchorEntity.addChild(modelEntityClone)
 arView.scene.addAnchor(anchorEntity)

*for point to measure distance to 3dobject

guard let rayResult = self.view!.ray(through: normalizedIndexPoint)else {return}
                let results = self.view!.scene.raycast(origin: rayResult.origin, direction: rayResult.direction)
                
                if let firstResult = results.first {
    var position = firstResult.position
     var distanceing = distance(firstResult.position, self.me!.position)
    }

I pointed very close to 3d object but it's a bit far saying 30 cm... or so, I found out that once I close to world origin, than it become almost 0...

how can I measure from 3d object not from world origin?