We've observed a potential race condition where the agent sends a duplicate of its previous message. This seems to occur when a new user message is received while the agent is actively processing a tool call (specifically sessions_spawn).

Steps to Reproduce:

1. The main session agent is given a task that requires a tool call which introduces a slight delay (e.g., sessions_spawn).
2. The agent sends its initial response message (e.g., announcing the sub-agent dispatch).
3. Immediately after this message is sent, while the tool call is still in-flight, the user sends a new message to the agent.
4. The timing appears to be critical, creating a race condition between the ongoing tool processing and the handling of the new inbound message.

Expected Behavior:
The agent should process the new user message normally (either after the tool call completes or by correctly queuing it), without sending any duplicate messages.

Actual Behavior:
The agent re-sends its previous response (the message sent just before initiating the tool call). This results in a confusing duplicate message appearing in the chat interface. A screenshot of this behavior has been captured.

Environment:

• OpenClaw Version: 2026.2.17
• Platform: Linux (Debian)
• Node.js Version: v24.13.1
• Channel: Telegram
• Agent Model in Use: gemini_official/gemini-2.5-pro

Additional Context:
No specific errors were observed in the gateway logs when this occurred. The issue seems to be related to the core message handling logic under concurrent load.