Bug type

Behavior bug (incorrect output/state without crash)

Beta release blocker

No

Summary

Version
OpenClaw 2026.4.2

Summary
A session does not reliably return to or stay on the configured primary model after fallback occurs. Even with openai-codex/gpt-5.4 configured as primary, the active session continues using a fallback model.

Minimal config

{
  "agents": {
    "defaults": {
      "model": {
        "primary": "openai-codex/gpt-5.4",
        "fallbacks": [
          "amazon-bedrock/minimax.minimax-m2.5",
          "openrouter/openrouter/free"
        ]
      }
    },
    "list": [
      {
        "id": "main",
        "model": "openai-codex/gpt-5.4"
      }
    ]
  }
}

Observed examples

• Fallback model got stuck on amazon-bedrock/minimax.minimax-m2.5
• After removing MiniMax from fallbacks, session used openrouter/openrouter/free instead of primary

Impact

• Users cannot trust the configured primary model to remain active.
• Model selection in the UI/session appears inconsistent after failover.

Steps to reproduce

Steps to reproduce

1. Configure openai-codex/gpt-5.4 as the primary model.
2. Configure one or more fallback models.
3. Start a normal session in the Control UI.
4. Cause the primary model to fail once so fallback activates.
5. After fallback succeeds, check the current model in the UI or via session status.
6. Attempt to switch back to openai-codex/gpt-5.4.

Expected behavior

Expected behavior

• The session should use openai-codex/gpt-5.4 by default.
• Fallback should only be used when the primary fails.
• After switching back, the current model should remain openai-codex/gpt-5.4.

Actual behavior

Actual behavior

• The session keeps using the fallback model after fallback occurred.
• Explicit switching back to openai-codex/gpt-5.4 appears inconsistent or temporary.
• Removing one fallback causes another fallback to be used instead of the primary.

OpenClaw version

2026.4.2

Operating system

MacOS 26.4

Install method

npm install

Model

openai-codex/gpt-5.4, minimax/m2.5, openrouter/free

Provider / routing chain

openclaw -> openai-codex/gpt-5.4 -> minimax/m2.5

Additional provider/model setup details

No response

Logs, screenshots, and evidence

Impact and severity

No response

Additional information

No response