FileManager memory leak

I have a memory leak problem with FileManager. My code is like this;

    func saveImageToDocumentDirectory(image: UIImage, name: String, then handler: @escaping () -> Void) {
     DispatchQueue.global(qos: .background).async {
        autoreleasepool {
            let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
            let fileName = name // name of the image to be saved
            let fileURL = documentsDirectory.appendingPathComponent(fileName)
            if let data = UIImageJPEGRepresentation(image, 0.2),!FileManager.default.fileExists(atPath: fileURL.path){
                do {
                    try data.write(to: fileURL)
                    handler()
                    print("file saved")
                } catch {
                    handler()
                    print("error saving file:", error)
                }
            }
        }
    }
}

After the handler response it does not remove from memory. For example It starts with 60MB then It rises 190MB, when all images saved, It does not down to 60MB.