Got unsupported file format 'org.webmproject.webp' when download PNG file from https url

• ImageSaver class:

class ImageSaver: NSObject {
    var successHandler: (() -> Void)?
    var errorHandler: ((Error) -> Void)?

    func writeToPhotoAlbum(image: UIImage) {
        UIImageWriteToSavedPhotosAlbum(image, self, #selector(saveCompleted), nil)
    }

    @objc func saveCompleted(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
        if let error = error {
            errorHandler?(error)
        } else {
            successHandler?()
        }
    }
}

• button action to trigger the download of a png file from URL:

Button{
let imageSaver = ImageSaver()

imageSaver.successHandler = {
    print("Success!")
   }
                        
imageSaver.errorHandler = {
    print("Oops: \($0.localizedDescription)")
  }

let imageRequestUrl = URL(string: lastImageUrl)!
// I'm sure that I can see the image url is valid and I can
// downloaded it from Google chrome successfully
print("imageRequestUrl:\(imageRequestUrl)")

let req = URLRequest(url: imageRequestUrl)
let task = URLSession.shared.dataTask(with: req) { d, res, err in
      if let data = d, let image = UIImage(data: data) {
             imageSaver.writeToPhotoAlbum(image: image)
           }
       }
task.resume()
}

• And this is the error:

findWriterForTypeAndAlternateType:119: unsupported file format 'org.webmproject.webp'

• More info

When I change the image URL to another one, like some other open-source png file, there's no error.... please help why it's so weird?