GitHub integration: collaborator's Claude sees private personal-account repo but cannot connect ('shows private') despite owner-side app install with All-repositories access

Symptom: A collaborator's claude.ai cannot read a private repository on a personal GitHub account. The repo appears in his Claude's GitHub UI but will not connect — reported by the user as "the repository is still showing private and not giving my Claude access." The repo owner's own claude.ai reads the same repo through the same integration without any problem.

Setup, verified by the owner (me) the same day:

• Repo: rpossum/MoneyBag, private, personal account (I'm the owner).
• The collaborator (rickringbakk) has full collaborator access — confirmed via gh api repos/rpossum/MoneyBag/collaborators; no pending invitations.
• The Claude GitHub App ("Claude", owned by anthropics) is installed on rpossum with All repositories (confirmed at github.com/settings/installations — installed ~6 months, predates the problem).
• The same app shows in my Authorized GitHub Apps, last used within the week; my claude.ai GitHub Integration reads the repo fine.
• No pending installation/permission requests on the owner account.

What the collaborator tried: connecting the GitHub Integration from claude.ai settings, closing/reopening the app and the site, retrying. Same result. (We are still verifying which GitHub identity his Claude authorized; if that turns out to be the cause I'll close this. But the symptom matches existing reports even when identity is correct.)

Looks related / possibly duplicate of: #33875, #68517, #18467, #12839, #27155 — the recurring "private personal-account repo not indexed on the backend despite correct app permissions" family. Filing anyway because the collaborator-vs-owner asymmetry (same repo, same app install: owner works, collaborator doesn't) is a data point I didn't see in those reports, and per-account backend indexing would explain it.

Expected: a collaborator whose GitHub identity has repo access, connecting through an app installation that covers the repo, should be able to read it — or at minimum get an actionable error instead of a silent "private" state.

Environment: collaborator on claude.ai (Pro) via macOS/browser + iOS app; owner on claude.ai (Max) via Windows/Chrome. Date: 2026-07-08.