Summary

Session auto-replies in Telegram forum groups consistently land in the General topic instead of the correct topic thread, even when:

• The topic is properly configured in channels.telegram.groups.<id>.topics.<threadId>
• The session's deliveryContext.threadId is correct
• The session state shows lastThreadId matching the topic
• Direct sends via the message tool with explicit threadId work correctly

Steps to Reproduce

1. Configure a forum group with topics in openclaw.json
2. Send a message in a specific topic (not General)
3. The gateway correctly routes to the session with the right threadSpec
4. The CLI processes and produces a reply
5. The reply is delivered to the group's General topic instead of the originating topic

Expected Behavior

Reply should include message_thread_id matching the topic the user messaged in.

Actual Behavior

Reply lands in General (topic 1). The message_thread_id parameter is not included in the sendMessage API call during session reply delivery.

Evidence

• Direct sends via MCP message tool with threadId parameter → lands in correct topic ✓
• Session auto-reply from same session with deliveryContext.threadId set → lands in General ✗
• Gateway log shows sendMessage ok chat=-100XXXXXXXXXX message=XXXX with no thread indicator
• No "retrying without thread" fallback triggered (checked logs)
• buildTelegramThreadParams and deliveryBaseOptions.thread appear correctly wired in source

Environment

• OpenClaw 2026.5.6 (c97b9f7)
• macOS (darwin)
• Telegram forum groups with topics enabled
• Affects both main and atlas2 agents
• Multiple groups confirmed affected (Atlas Command, Amplify)

Workaround

Using the message tool with explicit threadId for topic-targeted sends works. Session auto-replies do not.

Notes

The 2026.5.6 changelog mentions "Telegram forum-topic targets" fix, but the issue persists for the session reply delivery path specifically. The fix may have addressed runtime binding creation (parentConversationId) but not the final reply send.