unable to get all channel participants

[SofiaKonetskaya]

Code that causes the issue

import telethon

client = telethon.TelegramClient('bottest', api_id, api_hash, proxy=proxy
                                 ).start(bot_token=bot_token)
async def channelusers(channel_id):
    participants = client.iter_participants(channel_id)
    participants_ids = []
    async for participant in participants:
        participants_ids.append(participant.id)

Expected behavior

I expect to receive a list with the ids of all channel subscribers

Actual behavior

I get a list of 200 subscribers, although in reality there are more. Moreover, for groups (not channels) this code works correctly.
I also tried to get the list of participants using a While loop (code below), but it did not work - it only finds 202 participants:

while True:
    try:
        participants = client(GetParticipantsRequest(channel_id, ChannelParticipantsSearch(''), offset, limit, hash=0))
        if not participants.users:
            break
        all_participants.extend(participants.users)
        offset += len(participants.users)
        print(len(participants.users))

    except Exception as e:
       print(e)
       sys.exit()

Traceback

No response

Telethon version

1.33.1

Python version

3.7

Operating system (including distribution name and version)

Windows 10

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.

[Lonami]

The Telegram API refuses to return all participants, presumably to reduce spam. This is not something a library like Telethon can fix or work around.

[SofiaKonetskaya]

Thanks for your reply!
If it's not too much to ask. Could you tell me if it’s possible to use Telethon to delete all subscribers of the channel, which I am the administrator of, except for the specified list of participants.
I wanted to do this using a loop through all the participants, but apparently this is impossible.