Files.download does not start when number of files in folder is > 1000

This post https://stackoverflow.com/a/66227963/14414215 greatly helped in my understanding of how semaphore works and how implementing semaphores (besides using dispatchGroups) is able to properly control the files.download calls. 

   static func downloadMissingFiles(client: DropboxClient, callingProcess: String) {
      let fileManager = FileManager.default
      let localBaseURL = fileManager.urls(for: .cachesDirectory, in: .userDomainMask)[0].appendingPathComponent("Cloud/Dropbox", isDirectory: true)
      let semaphore = DispatchSemaphore(value: 1)  // insert desired concurrent downloads value here.

      // Data will be in the form of
      // key   : "/workouts/workout list 1/peye.mrc"
      // value : "//workouts/workout list 1/peye.mrc=_-_=015ca880b135d01000000020cb26de0"
      DispatchQueue.global().async { // Wrap the call within an async block
      for dbFiles in Array(dbFileNameRevDict) {
        semaphore.wait() // Decrement the semaphore counter
        let dbFilePathLower = dbFiles.key
        let dbFileNameRev = dbFiles.value
        let fullURL = localBaseURL.appendingPathComponent(dbFileNameRev)
        
        if fileManager.fileExists(atPath: fullURL.path) {
          print("  -> FILE EXISTS dbFileNameRev:\(dbFileNameRev)")
          localFileList.append(dbFileNameRev)
          semaphore.signal()  // Increment semaphore counter
        } else {
          let destination : (URL, HTTPURLResponse) -> URL = { temporaryURL, response in
            return fullURL
          }
          
          client.files.download(path:dbFilePathLower, overwrite: true, destination: destination)
            .response { response, error in
              if let (_, url) = response {
                print("====> DOWNLOADED:\(url.lastPathComponent)")
                // we've reached here means we've successfully download the file
                // So we can (release)increment semaphore counter
                semaphore.signal() 
              } else if let error = error {
               print(error)
            }
            /// This gives a progress of every single file on it's own. Hence, useless
            // .progress { progressData in
            //  print(progressData)
            // }
        }
      }
    }
   }
  }