[MODEL]

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Type of Behavior Issue

Claude ignored my instructions or configuration

What You Asked Claude to Do

I asked Claude to write and edit markdown files throughout a conversation. I have a CLAUDE.md memory instruction that says
"EVERY distinct block element in markdown MUST be separated by a blank line" and the model has been corrected on this dozens
of times across conversations.

What Claude Actually Did

1. When writing markdown files, Claude repeatedly outputs consecutive block elements without blank lines between them (e.g.

Date: April 2026\nDuration: 90 minutes on consecutive lines with no blank line separator)
▎ 2. This causes markdown renderers to collapse them into a single paragraph instead of separate lines
▎ 3. This is basic CommonMark spec — not an edge case
▎ 4. The model has a persistent memory/instruction explicitly about this issue and still violates it
▎ 5. Correcting it in-conversation fixes the immediate instance, but the model repeats the same mistake in the next file or
the next conversation
▎ 6. The model cannot self-fix — when asked why, it acknowledged the bug is in its weights/training and no amount of memory or
instructions reliably prevents it

Expected Behavior

When writing markdown files, all distinct block elements (consecutive bold-label lines, paragraphs, lists, tables) should be
separated by a blank line, per the CommonMark spec. This is especially important when the user has an explicit instruction in
CLAUDE.md reinforcing this rule. The model should produce valid, spec-compliant markdown without requiring the user to
manually review and fix formatting every time.

Files Affected

Permission Mode

Accept Edits was ON (auto-accepting changes)

Can You Reproduce This?

Yes, every time with the same prompt

Steps to Reproduce

▎ 1. Add a CLAUDE.md instruction stating that all markdown block elements must be separated by blank lines
▎ 2. Ask Claude to create a markdown file with metadata fields (e.g. "write a doc with Date, Duration, and Attendees fields in
bold")
▎ 3. Observe that Claude writes them on consecutive lines without blank lines between them, causing them to render as a single
paragraph
▎ 4. Correct Claude in-conversation — it will fix that specific instance
▎ 5. Continue working and ask Claude to write or edit another markdown file in the same conversation
▎ 6. Observe the same mistake repeated
▎ 7. The issue persists across conversations despite the CLAUDE.md instruction and correction history in memory

Claude Model

Opus

Relevant Conversation

Claude wrote a markdown file with the Write tool containing:
  ▎ **Date:** April 2026
  ▎ **Duration:** 90 minutes
  ▎ **Attendees:** Drew, Cesar, Vova...

These rendered as a single paragraph. When corrected, Claude fixed it. Later in the same conversation, Claude used the Write
   tool again to rewrite the full file and produced the same mistake in a different section (**By the numbers:** immediately
  followed by - list item with no blank line).

  ▎ When asked why, Claude said: "The honest answer is: this is a pattern in my weights that I can't self-debug, and telling me
  to 'remember harder' doesn't change the weights. The memory helps — I mess it up less than I would without it — but it doesn't
   eliminate it."

  ▎ The user has a CLAUDE.md instruction and a persistent memory file both explicitly requiring blank lines between block
  elements. The model acknowledges the rule, fixes individual instances when caught, but keeps generating the same invalid
  markdown.

Impact

Medium - Extra work to undo changes

Claude Code Version

2.1.89 (Claude Code)

Platform

Anthropic API

Additional Context

_No response_