Summary

In Telegram forum-topic sessions, heartbeat/system-event turns can preempt an in-progress user reply and make the original answer effectively disappear from the user's perspective.

This is not just heartbeat noise. The more serious effect is that a normal user question can get interrupted by heartbeat polls or async System: completion events before the assistant sends its final reply, and the unfinished reply does not automatically resume.

Environment

• OpenClaw: reproduced across 2026.4.8, 2026.4.9, and 2026.4.10
• Install: npm/pnpm global install on Ubuntu VPS
• Surface: Telegram group forum topic session
• Session shape: persistent main session bound to a Telegram topic

Repro pattern

1. User sends a normal message in a Telegram topic.
2. Assistant starts a multi-step response that uses tools or takes long enough to still be in progress.
3. Before the assistant sends the final user-visible reply, one of these arrives in the same session lane:
   • a heartbeat poll turn
   • an async exec completion / System: tool-completion event
   • a restart/config-patch completion event
4. The new turn runs first.
5. The original unfinished user reply does not automatically resume or get replayed.

User-visible result

From the user's point of view, it looks like:

• the assistant "stopped replying"
• a HEARTBEAT_OK or unrelated system completion appears instead
• the original answer is lost unless the user asks again

Why this feels distinct from existing heartbeat issues

There are already related issues about heartbeat/session contamination, but this one is specifically about user reply loss/preemption in the same active Telegram topic session.

Relevant issues I found:

• [Bug]: Heartbeat wakeups are persisted into main dashboard session as synthetic user messages #43168 Heartbeat wakeups are persisted into main dashboard session as synthetic user messages
• [Bug]: Heartbeat injects into active sub-agent sessions, terminating them with HEARTBEAT_OK #60926 Heartbeat injects into active sub-agent sessions, terminating them with HEARTBEAT_OK
• [Bug]: Possible regression: heartbeat sessions can re-trigger on local exec completed events and spam duplicate heartbeat log entries #46798 heartbeat sessions can re-trigger on local exec completed events and spam duplicate heartbeat log entries
• [Bug] Heartbeat and normal replies use parallel outbound paths without shared cross-source dedupe, causing duplicate / near-duplicate user-visible messages #60207 Heartbeat and normal replies use parallel outbound paths without shared cross-source dedupe
• [Bug]: async task completion reports can be lost because system event/wake is not reliably session-targeted #52305 async task completion reports can be lost because system event/wake is not reliably session-targeted

This issue is about the interaction of those classes of bugs with a live user-facing Telegram topic conversation, where heartbeat/system events appear to win the lane and the interrupted reply never comes back.

Current mitigation used locally

I mitigated this locally by changing heartbeat config to:

• agents.defaults.heartbeat.target = "none"
• agents.defaults.heartbeat.isolatedSession = true
• agents.defaults.heartbeat.lightContext = true

That reduces the visible problem a lot, but it feels like a workaround, not a real fix.

Expected behavior

Any of these would be acceptable:

1. Heartbeat/system-event turns should never preempt an in-progress user-visible reply in the same active session/thread/topic.
2. If preemption happens, the unfinished reply should automatically resume or be replayed after the system event turn completes.
3. Async/system completions should be routed into a separate non-preemptive lane for active user conversations.

Actual behavior

Heartbeat/system-event turns can occupy the same conversation lane and cause the original in-progress answer to vanish.

Extra note

Recent routing fixes that correctly send cron/subagent/restart messages back to the original thread/topic may be making this more visible on Telegram topics, because the noisy system events now land in the right place instead of disappearing elsewhere.