Event loop is closed.Called after closing the discord bot

Hello everyone. There is a rather unusual problem. I wrote a discord bot. It functions calmly and processes requests. But there is one moment. After completion (shutdown) the bot gives an error. Error:

Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x000001ED5B3B1F30>
Traceback (most recent call last):
  File "C:\Users\Семён Орехов\AppData\Local\Programs\Python\Python310\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\Семён Орехов\AppData\Local\Programs\Python\Python310\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\Семён Орехов\AppData\Local\Programs\Python\Python310\lib\asyncio\base_events.py", line 745, in call_soon
    self._check_closed()
  File "C:\Users\Семён Орехов\AppData\Local\Programs\Python\Python310\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x000001ED5B3B1F30>
Traceback (most recent call last):
  File "C:\Users\Семен Орехов\AppData\Local\Programs\Python\Python310\lib\asyncio\proactor_events.py", line 116, in __del__
  File "C:\Users\Семён Орехов\AppData\Local\Programs\Python\Python310\lib\asyncio\proactor_events.py", line 108, in close
  File "C:\Users\Семён Орехов\AppData\Local\Programs\Python\Python310\lib\asyncio\base_events.py", line 745, in call_soon
  File "C:\Users\Семён Орехов\AppData\Local\Programs\Python\Python310\lib\asyncio\base_events.py", line 510, in _check_closed
RuntimeError: Event loop is closed

The bot issues such an error after the program is completed. How to fix it?
Solutions like:

• change token
• token is invalid

These solutions didn't help me. 

The only thing I have improved all the libraries that were. Discord itself, aiohttp and asyncio. But they did not lead to a result. What can such a problem be related to? Bot code, example:

import discord

    TOKEN = 'token'
    class MyClient(discord.Client):
        async def on_ready(self):
            print('Logged on as', self.user)

    async def on_message(self, message):
        # don't respond to ourselves
        if message.author == self.user:
            return

        if message.content == 'ping':
            await message.channel.send('pong')


client = MyClient()

client.run(TOKEN)