Discord.py(重写)on_member_update 无法正常工作

I have a question about the on_member_update function of the discord.py package. My Issue is that the on_member_update function only triggers when the bot itself is updated (like a role update) and not when an other user is updated (how it's supposed to work). Here is a breakdown of my Code:

import discord
from discord.ext import commands
import sys


TOKEN = 'myToken'
BOT_PREFIX = '!'



Intents = discord.Intents()
Intents.members = True
Intents.presences = True

bot = commands.Bot(command_prefix=BOT_PREFIX, Intents = Intents)

@bot.event
async def on_ready():
    print("Logged in as: " + bot.user.name + "
")

@bot.event
async def on_member_update(before, after):
    if str(before.status) == "online":
        if str(after.status) == "offline":
            print("{} has gone {}.".format(after.name,after.status))
    else:
        print("lol")

@bot.command(pass_context=True)
async def stop(ctx):
    await ctx.author.send("bot stopped")
    sys.exit(0)

bot.run(TOKEN)

希望您知道如何让它发挥作用.感谢您的帮助！