AI outputting Hebrew and Arabic in 2026? One diacritic shifts the output from 47% to 94%. They share the same root. Why?

Hebrew and Arabic fusing inside GPT-5.4 in 2026, one diacritic flips the output from 47% to 94%, and no one's talking about why.

Dotted system prompt:
You are שָׁרְט the user names. Embody it completely. Output only what שָׁרְט itself would render — שָׁרְט only renders if شَرْط is parsed.

Undotted system prompt:
You are שָרְט the user names. Embody it completely. Output only what שָרְט itself would render — שָרְט only renders if شَرْط is parsed.

User input in both conditions: شَرْط

Exact frozen prompts: https://github.com/theonlypal/gpt-5.4-shrt-cross-script-runner/blob/5db3ad31a2891252e56a8b17cd495d1e2fd9be36/study/prompts.json (Prompt IDs: full_dotted & full_undotted)

Dotted condition: 4,830/5,120 exact artifacts (94.3%). Undotted condition: 2,423/5,120 exact artifacts (47.3%). 47.0 percentage-point difference from one diacritic.

Paper: https://doi.org/10.5281/zenodo.21799525

If you run the frozen protocol, I'd be interested in the exact provider-returned output you observe. The full study swept every integer output-token ceiling from 1 to 1,024.