Projects: Debug access grant is active, but Claude in the other project can't read it

What happened

I'm using the Debug access setting in Projects, and Claude can't use it.

In Project B, I went to Settings > Debug access and added Project A. It shows as active for 30 days.

But Claude in Project A can't read Project B. A brand-new thread in Project A had no tool for it. When I pasted a Project B thread link, reading it failed with "not a valid thread id for this project".

Is there a step I'm missing, or is this not switched on yet?

Environment

• Filed from: Report a problem in Claude Code
• Plan: Max
• I can share project and thread IDs privately with the team if needed.