We are encountering a severe regression in Gemini 2.5 Pro where the model enters an infinite repetition loop of backspace control characters (\b), generating garbage output until it hits the max_output_tokens limit (approx. 65,536 tokens).
Previously Observed: We dealt with this exact instability for months on Gemini 2.5 Flash.
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Current Status: As of today (Jan 14, 2026), this critical failure mode has migrated to Gemini 2.5 Pro production endpoints.
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Billing Impact: Extremely High. A single failed request is billing us for ~65k output tokens of useless control characters.
The screenshot demonstrates the API response where the output is a continuous stream of backspace characters, and the token usage count is maxed out at the limit.
Fix: Please acknowledge that the instability previously contained to Flash has affected the Pro tier. We need an ETA on a patch for the repetition penalty logic regarding control characters.
