Bug: Unexpected model fallback after successful response #9549
Description
Summary
Automatic model fallback triggered after a successful response from the primary model, not due to a failure.
Environment
- OpenClaw version: latest (as of 2026-02-04)
- Primary model:
ollama/qwen3:32b - Fallback chain:
[qwen3:32b, gpt-oss-agentic]
Timeline (from session transcript)
| Time | Event |
|---|---|
| 10:58:33 | Session start with qwen3:32b |
| 10:58:54 | First response (greeting, 21s) |
| 11:03:11 | Tool-call with validation error (missing action: param) |
| 11:04:12 | Retry succeeds with action: send (61s total turn) |
| 11:04:58 | Unexpected switch to gpt-oss-agentic (no model_change event, only model-snapshot) |
| 11:05:07 | gpt-oss responds (9s) |
Expected Behavior
Model should remain on qwen3:32b since:
- The response was successful (tool call completed)
- No explicit
/modelcommand was issued - No error or timeout occurred
Actual Behavior
Fallback to next model in chain triggered silently after successful completion.
Notes
- No
model_changeevent in transcript — onlymodel-snapshotshows the switch - Gateway logs from that time are rotated/unavailable
- Possibly related to the 61s response time? But that's not a timeout.