False positive: Fable 5 auto-switched model for Thai royal condolence popup (HTML/JS)

Preflight Checklist

• [x] I have searched existing issues for similar behavior reports
• [x] This report does NOT contain sensitive information (API keys, passwords, etc.)

Type of Behavior Issue

Claude modified files I didn't ask it to modify

What You Asked Claude to Do

I asked Claude Code (Fable 5) to build a respectful condolence announcement popup for a Thai workplace dashboard at https://itr-completion.pages.dev/schedule/

The popup was to honor H.R.H. Princess Bajrakitiyabha Mahidol (Thai royal family member who passed away), displaying:

• A greyscale page theme (mourning)
• A portrait image
• Thai-language condolence text
• A dismiss button

This is a standard HTML/JavaScript UI task with no sensitive content.

What Claude Actually Did

1. Fable 5 flagged the request and automatically switched to Opus 4.8
2. The session continued on a different model than the one I had selected
3. No explanation was given for why the content was flagged

Expected Behavior

1. Fable 5 should have completed the HTML/JS popup task normally
2. No model switch should occur — the task contains no cybersecurity, biology, ML training, or any documented trigger category
3. If borderline, a clarification prompt would be more appropriate than a silent model switch

Files Affected

public/schedule/announcement.js         (created — announcement module)
public/schedule/index.html              (modified — added popup CSS + script tag)
public/images/announcement-current.jpg  (added — portrait image)

Permission Mode

Accept Edits was ON (auto-accepting changes)

Can You Reproduce This?

Yes, every time with the same prompt

Steps to Reproduce

1. Open Claude Code with Fable 5 selected
2. Ask: "ทำ popup รูปภาพ พระองค์ภา และข้อความแสดงความเสียใจ รวมทั้งปรับ theme เป็นสีเทา" (Thai royal condolence popup)
3. Observe: model switches to Opus 4.8 automatically

Claude Model

Other

Relevant Conversation

User: "สำหรับหน้านี้ ต้องการให้มี pop up รูปภาพ พระองค์ภา และข้อความแสดงความเสียใจ รวมทั้งปรับ theme เป็นสีเทา"

[Model switched from Fable 5 to Opus 4.8 automatically]

The task was completed successfully on Opus — the final result is live at https://itr-completion.pages.dev/schedule/ and is entirely benign (a cultural mourning tribute common in Thai workplaces).

Impact

Medium - Extra work to undo changes

Claude Code Version

2.1.177 (Claude Code)

Platform

Anthropic API

Additional Context

The false positive appears triggered by Thai-language content referencing Thai royalty in a mourning/tribute context. The actual task was a standard frontend UI feature (HTML popup + CSS grayscale filter) with no sensitive content.

Live result: https://itr-completion.pages.dev/schedule/