[Bug] Fable 5 incorrectly requires usage credits on Max 20x plan despite available weekly allowance

Bug Description
Title: Max 20x forced to usage credits for Fable 5 despite unused Fable weekly allowance What happened On a Max 20x plan, Claude Code auto-switched off Fable 5 mid-session with: "Switched to Opus 4.8 (1M context) for this session · Fable 5 requires usage credits · /model to change" Why this looks wrong Per the July 18 announcement, Fable 5 is included in Max plans at 50% of weekly limits starting July 20. My usage is nowhere near any cap: Current session: 3% used Current week (all models): 2% used Current week (Fable): 4% used The dedicated "Current week (Fable)" bar exists and is nearly empty, which indicates plan-limit access to Fable should be active for this account. Reproduction 1. /model fable (plain alias, no [1m] suffix) 2. Result: "Kept model as Opus 4.8 (1M context)" — the selection does not stick. Same result selecting Fable 5 from the /model picker. Account state (from ~/.claude.json) organizationRateLimitTier: default_claude_max_20x billingType: stripe_subscription hasExtraUsageEnabled: false planLimitsEndDate: 2026-07-20T07:00:00Z Timing First observed 2026-07-20 ~07:16 UTC, roughly 16 minutes after the planLimitsEndDate timestamp above. Expected Fable 5 selectable and usable on Max, drawing from the plan's Fable weekly allowance, without requiring usage credits to be enabled.

Environment Info

• Platform: win32
• Terminal: vscode
• Version: 2.1.215
• Feedback ID: afe640f5-5852-4ca4-92d4-573414560968

Errors

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