Telethon doesn't retrieve last messages from the chat

Question

I have this code:

messages = []
async for message in client.iter_messages(chat):
    messages.append(message)
    if len(messages) >= 10:  # change this number to retrieve more or less messages
        break

Previously it worked good and the code retrieved last messages from the chat. But since 5 of May it stopped to retrieve last messages. Now the results look like.

But i didn't change anything in the code and didn't update library or something else. Why the code doesn't retrieve the last messages?

Please help me to understand what is wrong here. I just need to retrieve last messages from telegram chat.