Prompt suggestions not appearing despite CLAUDE_CODE_ENABLE_PROMPT_SUGGESTION=true (v2.1.66)

Description

Prompt suggestions (grayed-out follow-up prompts in the input field) are not appearing at all, despite being enabled.

Environment

• Claude Code version: 2.1.66
• OS: macOS (Darwin 25.3.0)
• Shell: zsh

Configuration

# ~/.zshrc
export CLAUDE_CODE_ENABLE_PROMPT_SUGGESTION=true

Verified the env var is loaded correctly in the Claude Code session.

Expected behavior

After Claude responds, a grayed-out suggested prompt should appear in the input field.

Actual behavior

No suggestions appear at any point during the conversation — not after first response, not in multi-turn conversations.

Likely cause

Related to the prompt suggestion cache regressions that were fixed in v2.1.49, v2.1.50, and v2.1.62 (per changelog). The issue appears to persist or has regressed again in v2.1.66.

Related issues

• #17572 (closed as duplicate of #14629)