openclaw - 💡(How to fix) Fix [Bug]: gemini-3-flash-preview cron sessions downgrade thinkingDefault "low" to "off" in 2026.5.18 — worked in 4.23

Bug type

Regression (worked before, now fails)

Beta release blocker

No

Summary

In v2026.5.18, isolated cron sessions emit a warning and silently downgrade thinkingDefault: low to off for google/gemini-3-flash-preview. This was not the case in v2026.4.23 where think low worked correctly in the same cron environment.

Steps to reproduce

Configure OpenClaw with google/gemini-3-flash-preview as model and thinkingDefault: low in openclaw.json Create any isolated cron job (e.g. morning briefing, scheduled digest) Wait for the cron job to trigger, or manually run: openclaw cron run <cron-id> Check gateway logs — warning appears immediately at cron session startup:

Thinking level "low" is not supported for google/gemini-3-flash-preview; downgrading to "off" Note: Reproducible across multiple different cron jobs (confirmed on at least 2 separate cron session IDs). Did not occur on v2026.4.23 with identical configuration.

Expected behavior

Cron sessions run with thinkingDefault: low as configured. This worked correctly in v2026.4.23 with the same model and configuration.

Actual behavior

5.18 silently downgrades think low to off for gemini-3-flash-preview in cron sessions, emitting a warning. The model's thinking capability is not being used despite explicit configuration.

OpenClaw version

2026.5.18 (50a2481)

Operating system

Rocky Linux 10.1

Install method

No response

Model

google/gemini-3-flash-preview

Provider / routing chain

Google AI Studio (GEMINI_API_KEY)

Additional provider/model setup details

No response

Logs, screenshots, and evidence

[cron:763edefb-89bc-4096-aa27-d76a1edb9eb6] Thinking level "low" is not supported for google/gemini-3-flash-preview; downgrading to "off".
[cron:0e64d16b-633d-4df7-860d-adf281546049] Thinking level "low" is not supported for google/gemini-3-flash-preview; downgrading to "off".

Impact and severity

No response

Additional information

Two separate cron session IDs show the same downgrade behavior, confirming this is systematic and not a one-off occurrence. The warning suggests 5.18 changed the thinking level support detection logic for this model.