AddBlob() in OSC Plugin doesn't work well.

I want to send byte arrays using the OSC plugin, but with a blueprint like the one below, the data received at the server is not what I expect.
{0, 1, 2, 3, 1, 2, 3, 4} is received instead of {0, 1, 2, 3, 4, 5, 6, 7}.
The same problem is occured in equivalent C++ code.
Please tell me how to fix this problem.

Blueprint(Client)

Python(Server)

import argparse

from pythonosc.dispatcher import Dispatcher
from pythonosc import osc_server

def print_bytes_handler(unused_addr, args, bytes):
  print("[{0}] (len: {2}) ~ {1}".format(args[0], ' '.join(map(str, bytes)), len(bytes)))

if __name__ == "__main__":
  parser = argparse.ArgumentParser()
  parser.add_argument("--ip",
      default="127.0.0.1", help="The ip to listen on")
  parser.add_argument("--port",
      type=int, default=7000, help="The port to listen on")
  args = parser.parse_args()

  dispatcher = Dispatcher()
  dispatcher.map("/test1", print_bytes_handler, "TEST1")
  server = osc_server.ThreadingOSCUDPServer(
      (args.ip, args.port), dispatcher)
  print("Serving on {}".format(server.server_address))
  server.serve_forever()

environment:
Windows10, UnrealEngine5.1.1