[BUG] Cowork Global instructions cache never refreshes — persists even after clearing the field, quitting all Claude apps, and starting brand new conversations

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Environment: macOS (Mac mini), Claude Desktop, Cowork mode

Summary:
A stale Global instructions document (dated 2026-06-21) continues to be injected verbatim into brand new Cowork conversations, despite the document having been edited and re-saved correctly multiple times over several days, and despite fully clearing the Settings field and restarting the app. The Settings UI display and the actual injected content are demonstrably decoupled.

Steps to reproduce:

1. Settings > Cowork > Global instructions — edit and save new content; confirmed correct immediately after saving
2. New conversations continue to receive OLD content (verbatim match to a version last edited weeks earlier) instead of the saved one
3. Isolation test: clear Settings > Cowork > Global instructions completely (empty field), confirmed empty, then fully quit all Claude apps and relaunch
4. Global instructions field remains empty in Settings after relaunch (confirmed) — rules out the Settings field itself silently reverting
5. Despite the empty Settings field, a brand new Cowork conversation still receives a full, verbatim copy of the OLD instructions document (dated weeks earlier) under a system block labeled "claudeMd" / "user's private global instructions for all projects"
6. Repeated with a third, independent brand-new conversation, Settings re-verified empty in the UI at the time of testing: same result — full stale v1.3 document injected under claudeMd
7. On disk, ~/Library/Application Support/Claude/local-agent-mode-sessions/<session-id>/<thread-id>/memory/CLAUDE.md was independently found to contain the same stale content, timestamped after a Settings save — indicating a persistent cache separate from the Settings UI

Expected: with Settings > Cowork > Global instructions empty, new conversations should receive no injected global instructions content; when Settings holds saved content, new conversations should receive that exact content

Impact: any edit to Global instructions is silently ignored across every new conversation; the Settings UI does not reflect what is actually being injected, with no user-visible way to detect or clear this cache

Workaround found: a CLAUDE.md file placed at the root of a connected desktop folder is read correctly and can override the stale injected content by instructing Claude to check a version-tracking file and load current instructions from disk instead — suggesting the bug is isolated to the Global-instructions-in-Settings storage/propagation path

What Should Happen?

With Settings > Cowork > Global instructions empty, new conversations should receive no injected global instructions content. When Settings holds saved content, new conversations should receive that exact content, matching what's displayed in Settings.

Error Messages/Logs

Steps to Reproduce

1. Settings > Cowork > Global instructions — edit and save new content; confirmed correct immediately after saving
2. Open a new Cowork conversation — Claude reports OLD content instead of the one just saved
3. Clear Settings > Cowork > Global instructions completely (empty field), confirm empty, then fully quit and relaunch all Claude apps
4. Global instructions field remains empty in Settings after relaunch (confirmed)
5. Open a brand new Cowork conversation anyway — it still receives a full, verbatim copy of OLD instructions content (dated weeks earlier) under a system block labeled "claudeMd"
6. Repeated with two more independent brand-new conversations, Settings re-verified empty each time — same result

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

N/A — using Claude Desktop (Cowork mode), not the Claude Code CLI

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_