Claude Code quality degraded significantly in recent 3 days

Description

Claude Code quality has dropped noticeably over the past 3 days (around 2026-04-06 to 2026-04-08).

Symptoms

• Need to repeat instructions multiple times before Claude follows through completely
• Fails to proactively clean up stale references when making changes (e.g., had to ask 3 times to remove outdated identifiers from docs after a conceptual change)
• Responds too quickly without thinking carefully, leading to shallow answers that need correction
• Overall less thorough and less autonomous compared to previous weeks

Environment

• Claude Code CLI
• Model: Claude Opus 4.6 (1M context)

Expected behavior

Claude Code should follow existing project instructions (CLAUDE.md), think before responding, and proactively handle related changes in one pass without requiring repeated prompts.