Claude attributes other AI models work to itself since Sept 16 update

Bug description
Claude used to correctly distinguish its own output from other AI models.

Since the Sept 16 update, when shown screen recordings of Meta AI generating videos, Claude said "Claude está generando vídeos de 10 segundos con tu nombre" — attributing Meta AI's video generation to itself. The Meta AI interface was clearly visible (the "Instantáneo" button, different UI layout) but Claude identified it as its own mobile app.

Steps to reproduce

1. Send screen recordings showing Meta AI generating content
2. Claude describes the content as its own work
3. Claude says "Claude está generando" instead of "Meta AI está generando"

Expected behavior
Claude correctly identifies which AI model is performing the work shown in screenshots.

Actual behavior
Claude claims the work of Meta AI as its own. Narcissistic hallucination.

Environment
All models: Opus 4.6, Opus 5.5, Sonnet 4.6
Pro subscriber.
Related issues: #96308 #96329 #96745 #96892 #97113 #97119 #97120 #97200