[BUG] Cowork: pinning a project removes its sessions from Recents — Recents becomes useless as you organize (macOS)

What's Wrong?

In Claude Desktop (Cowork), pinning a project silently removes all of that project's sessions from the Recents list. The sessions still exist, still open fine, and still appear under "View all" — they are simply excluded from Recents.

The practical result: the more projects you pin, the blinder Recents gets. I have ~17 pinned projects. Nearly all of my actual work lives in them, so Recents can only ever show unfiled scraps. My four most recent sessions are all invisible in Recents while week-old unfiled chats sit at the top. A recency list that systematically hides your most recent work is worse than no list at all.

This is not a data-loss or indexing bug (distinct from #69663 and #51412) — nothing is lost, and "View all" renders everything in correct recency order. The two lists simply disagree.

Isolated reproduction

Reproduced cleanly on a second, near-empty instance with one variable changed:

1. Create a project (Lot 10). Leave it unpinned.
2. Start a Cowork session inside it (Project test session).
3. Look at Recents → the session is listed. ✅
4. Now pin Lot 10. Change nothing else.
5. Look at Recents → the session is gone. It now renders only under the pinned Lot 10 node in the sidebar.

Same session, same instance, one variable: pinned state.

This also explains the behavior on my main instance exactly:

| Session | Project | Pinned? | In Recents? |
|---|---|---|---|
| Help and user guide search | Product Support Lifecycle | yes | ❌ |
| Cortex login invalid token | Cortex | yes | ❌ |
| Cortex Steward operations | Cortex | yes | ❌ |
| Agentlab data sync issue | Cortex | yes | ❌ |
| Gate closure issue | Drive Gate System | no | ✅ |
| Project test session | Lot 10 | no → yes | ✅ → ❌ |

Ruled out

• Not a filter. Reproduced with Recents filters set to Type = All, Status = All, Last activity = All.
• Not data loss. Every affected session is present in View all and opens normally.
• Not project membership per se. Unpinned-project sessions (Gate closure issue, Project test session pre-pin) appear in Recents fine. Pinned state is the determining variable.

What Should Happen?

Recents should list recent sessions by recency. Pinning is an additive gesture everywhere else in the app — "this matters, keep it handy." Here it is subtractive: it removes work from the one list whose entire purpose is showing you what you just touched. Pinning your most important projects should not be the thing that hides your most important work.

At minimum, this behavior should be documented and opt-out-able. Ideally Recents should be recency-scoped, full stop, and the existing Type/Status/Last-activity filter menu is the natural place for a "hide pinned-project sessions" toggle if some users want the current behavior.

Is this a regression?

I believe so — this is not how it previously behaved. I can't pin the exact version it changed in. The most plausible candidate is the July 7, 2026 change: "Chat and Cowork also share one home now, with one place for your projects and artifacts across both" — a sidebar restructure of exactly the kind that would rewrite Recents scoping. Nothing in the release notes mentions Recents scoping changing.

Documentation gap

Recents is not defined anywhere in the Cowork help docs. I read Get started with Claude Cowork, Organize your tasks with projects in Claude Cowork, and Use Claude Cowork on web, desktop, and mobile end to end — none describes what Recents contains or how pinning affects it. There is no published spec to check this against, which is why it reads as broken rather than intentional.

Claude Code Version

Claude for Mac 1.21459.3 (e0f338)

Platform

Claude Desktop (Cowork)

Operating System

macOS

Additional Information

Reproduced across two separate Claude Desktop instances on the same machine.