Switch Case not executing - No case is met

Question

I have the following code to check which radio button is clicked by the user.

@IBAction func text_radio_changed(_ sender: Any) {
           var text_position:WatermarkPosition
           let button:NSButton = sender as! NSButton
           let id:String = button.identifier!.rawValue
           switch id {
           case "topleft":
               text_position=WatermarkPosition.topleft
           case "topcenter":
               text_position=WatermarkPosition.topcenter
           case "topright":
               text_position=WatermarkPosition.topright
           case "leftsidecenter":
               text_position=WatermarkPosition.leftsidecenter
           case "center":
               text_position=WatermarkPosition.center
           case "rightsidecenter":
               text_position=WatermarkPosition.rightsidecenter
           case "bottomleft":
               text_position=WatermarkPosition.bottomleft
           case "bottomcenter":
               text_position=WatermarkPosition.bottomcenter
           case "bottomright":
               text_position=WatermarkPosition.bottomright
           default:
               text_position=WatermarkPosition.center
        }
    }

On debugging I can find the the value of id is properly passed but does not enter any switch

Setting identifier