receive event update twice on ChatAction with two different action_message on user_joined

[winxen]

Code that causes the issue

Expected behavior

I was trying to write a bot to detect and record whenever a new user joining group chat. And trying to use event.user_joined to do so, but whenever user join the group the bot would receive update event twice, one come with action_message=MessageService and user_joined=True and another one action_message=None and user_added=True.
Both events show it came from the same user and the same group, I wonder if this was cost by a bug in library or it just a normal behavior from telegram server itself, and the problem is that sometime it only send one among the two(randomly) which make it hard for which event I should focus on to determine if there a user joined group

Actual behavior

Traceback

No response

Telethon version

Telethon 1.29.2

Python version

Python 3.11.4

Operating system (including distribution name and version)

macOS 13.4.1

Other details

No response

Checklist

• The error is in the library's code, and not in my own.
• I have searched for this issue before posting it and there isn't an open duplicate.
• I ran pip install -U https://github.com/LonamiWebs/Telethon/archive/v1.zip and triggered the bug in the latest version.