In a forum supergroup with Topics enabled, a Rich Message composed and sent inside a non-General topic loses its topic. Steps to reproduce: 1) open a non-General topic in a forum supergroup; 2) compose a Rich Message there and send it; 3) read that message through the Bot API with a bot that is a member of the group. Expected: the message carries message_thread_id for that topic and is_topic_message: true, exactly like a plain text message sent in the same topic. Actual: it arrives with no message_thread_id and no is_topic_message at all, so it is attributed to the General topic. Not reproducible on iOS: the same Rich Message composed and sent from Telegram for iOS in the same topic arrives with the correct message_thread_id and is_topic_message: true. A plain text message sent from the macOS app in that same topic is also correct, so only the Rich Message path drops the topic.
Steps to reproduce
Create a supergroup, enable Topics, and create a topic other than General. 2. Add any bot to the group as a member. 3. In Telegram for macOS, open that topic (not General). 4. Open the rich-text editor and compose a Rich Message - for example a bold paragraph and one more paragraph. 5. Send it. 6. On the bot side, read the incoming update via getUpdates or a webhook. 7. The message object has no message_thread_id and no is_topic_message, so it looks like a General-topic message. 8. Repeat steps 3-7 from Telegram for iOS in the same topic: the message arrives with the correct message_thread_id and is_topic_message: true. 9. Repeat steps 3-7 from Telegram for macOS with a plain text message instead of a Rich Message: that one is also correct.
Device info
Telegram macOS 12.10 (282985) STABLE, MacBook Pro M3 Pro, 27.0