Environment for both captures: Linux web development app, Chromium preview browser, 1280 x 800 CSS pixels, dark theme. Each commit runs from its own detached worktree and fresh database with T3CODE_DEV_SEED=0. Synthetic conversations only.

Original reproduction attempted on both: add Factory Droid 1.7.1 from ACP Registry, skip sign-in, select Default in a new thread, send Hello. Both remained Working rather than emitting auth_required. This does not verify the intermittent Factory Droid failure or successful sign-in/retry.

Controlled reproduction, identical on both:
1. Add a Local ACP command pointing to auth-required-peer.cjs; label ACP auth required.
2. Leave the peer unarmed during discovery (no .armed file beside it), refresh provider status, and select its Default model in a new thread.
3. Create the peer's .armed marker file before sending a message. Every subsequent session/new returns JSON-RPC error -32000, Authentication required. This changes only the external peer, never T3 application code or persisted failure text.
4. Start recording, type Hello, submit, inspect the error banner and Provider session failed to open item.
5. Dismiss error, inspect the persistent item, stop recording.

Observed: base renders a generic Failed to open acpRegistry provider session error containing an internal identifier in both places. Head renders The provider needs you to sign in. Sign in from its provider settings or with its own CLI or app, then retry the turn. in both places, without the identifier.

AI-assisted; verified with the tests and tools listed above.