[Remote Control / Projects] AskUserQuestion from a Remote Control session never appears in the mobile app; thread stays stuck

Surface: Claude mobile app, Projects (beta), in a thread whose work runs as a Claude Code Remote Control session on a desktop machine. Observed 14 Oct 2026.

Steps to reproduce

1. In a Project, start a thread backed by a Remote Control session on a laptop or desktop.
2. Have that session call the AskUserQuestion tool.
3. Open the thread in the Claude mobile app.

Expected
The question appears in the thread as a tappable card (as ask_decision cards do), or a typed reply in the thread answers or cancels it.

Actual

• Nothing appears on mobile. The thread just looks idle.
• Messages typed in the thread queue behind the pending question. A typed "yes" did not unblock it.
• Other Claude sessions in the project can't unblock it either: send_message to the Remote Control session is refused, and message_thread is delivered but also queues.
• Three sessions stayed blocked for about an hour, until the questions were answered from a desktop.

Impact
For anyone working mainly from a phone, every session that asks a question stalls silently until they reach a computer.

Related
On 12 Oct 2026, a tap on an ask_decision card in a thread also never reached the Remote Control session working that thread.