[Bug] Anthropic API Error: False positive safety flag with Fable model on rephrase request

Bug Description
I asked claude code with /model set to Fable 5 with /effort xhigh to rephrase a sentence in a LaTeX document. It suggested a reworded sentence and i told it I didn't like one of its words... "prescription". so I told it please rephrase again using another word so you're not using the word "prescription". Then it had a total anneurysm and the message was flagged (twice) by Fable 5's safeguards. Falsely so, I think.

Environment Info

• Platform: win32
• Terminal: xterm-256color
• Version: 2.1.228
• Feedback ID: 21efd344-6e0a-4995-b9a8-0f9df27d7fcb

Errors

[{"error":"TelemetrySafeError: VirtualMessageList: itemKeys/messages length desync (keys=1960 messages=1959 range=[1930,1960))\n    at DrE (B:/~BUN/root/src/entrypoints/cli.js:23308:33100)\n    at R2m (B:/~BUN/root/src/entrypoints/cli.js:23308:26024)\n    at Co (B:/~BUN/root/src/entrypoints/cli.js:1985:21352)\n    at gu (B:/~BUN/root/src/entrypoints/cli.js:1985:40441)\n    at B_e (B:/~BUN/root/src/entrypoints/cli.js:1985:51364)\n    at Rie (B:/~BUN/root/src/entrypoints/cli.js:1985:89049)\n    at G_e (B:/~BUN/root/src/entrypoints/cli.js:1985:87997)\n    at fee (B:/~BUN/root/src/entrypoints/cli.js:1985:87816)\n    at KN (B:/~BUN/root/src/entrypoints/cli.js:1985:84078)\n    at Ye (B:/~BUN/root/src/entrypoints/cli.js:1985:6655)","timestamp":"2026-08-17T08:14:23.197Z"}]