Implicit topic creation in private chats: follow-up text message is delivered without message_thread_id
Platform
Telegram Android
Description
When a user types in the “All” lane to start a new topic in a private chat with topics enabled, Telegram sends two separate updates:
A service message with forum_topic_created and a valid message_thread_id.
The user’s actual text message — but this message arrives without message_thread_id, is_topic_message, or reply_to_message.
Because the text message lacks a thread ID, it is indistinguishable from a General/lobby message. Bots and clients cannot tell that it belongs to the newly created topic. The new topic is created, but the user’s message is not routed into it.
Steps to reproduce
Enable topics in a private chat.
Open the “All” lane.
Type a message to start a new topic implicitly.
Inspect the updates via Bot API getUpdates or MTProto.
Observe the service message carries a message_thread_id, while the following text message does not.
Reproduced on Telegram Android v13.0.2 7175 store bundled arm64-v8a. > In a private bot chat with topics enabled: 1. Send a message from All Messages to implicitly create a topic. 2. A new topic is created, but the sent message remains in the main chat rather than appearing inside that topic. 3. The bot’s reply also appears in the main chat. > Expected: the initial message and the bot’s reply belong to the newly created topic. > Please also check the report’s platform category: it currently says Telegram Desktop, but this reproduction is on Android.
Telegram Android v13.0.2 7175 store bundled arm64-v8a.
>
In a private bot chat with topics enabled:
1. Send a message from All Messages to implicitly create a topic.
2. A new topic is created, but the sent message remains in the main chat rather than appearing inside that topic.
3. The bot’s reply also appears in the main chat.
>
Expected: the initial message and the bot’s reply belong to the newly created topic.
>
Please also check the report’s platform category: it currently says Telegram Desktop, but this reproduction is on Android.