Claude iOS app: Project Instructions not loaded into conversation context

Bug Description

Project Instructions (custom system prompts) set on a Claude Project are not loaded into conversation context on the iOS mobile app. The same project works correctly on desktop (claude.ai).

Steps to Reproduce

1. Create a Project on claude.ai (desktop) with custom Instructions
2. Add a simple instruction, e.g.: "Always respond in Japanese. Every response must start with 'TEST:'"
3. Verify it works on desktop — Instructions are followed correctly
4. Open the same project on the Claude iOS app
5. Start a new chat within the project
6. Send a message that should trigger the Instructions

Expected Behavior

The Instructions should be loaded and followed, same as on desktop.

Actual Behavior

Claude responds as if no Instructions exist — completely generic responses with no awareness of the project context. Even a single-line instruction is ignored.

Troubleshooting Attempted

• Force-closed and reopened the app
• Logged out and back in
• Started new chats (not reusing old ones)
• Simplified Instructions to a single line — still not loaded
• Confirmed the Project Files section shows uploaded files on mobile
• Confirmed Instructions section shows the saved text on mobile

Environment

• iOS app (latest version as of 2026-04-06)
• Desktop claude.ai works correctly for the same project
• Account: Pro plan

Impact

This blocks mobile use of Projects entirely. Users who set up Projects on desktop and expect to use them on mobile get no benefit from their Instructions or uploaded knowledge files.