Remote Control: 'Failure to load session' on Max plan - was working, now broken

Bug Description

Remote Control pairing has completely stopped working as of ~March 30, 2026. Was working perfectly before, no changes made on user side. Now fails every time.

Environment

• Claude Code version: 2.1.89 (latest)
• Plan: Max (paying customer)
• OS: macOS Darwin 25.3.0 (Apple Silicon)
• Device: iPhone (iOS Safari)

Steps to Reproduce

1. Run claude remote-control — connects successfully, shows bridge URL and QR code
2. Scan QR code with iPhone camera — URL banner appears, tap it
3. Opens claude.ai but does NOT load the session — just shows main page
4. Try opening bridge URL directly (https://claude.ai/code?bridge=...) — same result, redirects to main page
5. Try opening direct session URL (https://claude.ai/code/session_...) — shows "Failure to load session" error

What Was Tried

• Logging out and back in on CLI (claude auth logout && claude auth login)
• Running with --verbose flag — shows session created successfully on local side
• Verified subscription is active (Max plan)
• Verified version is latest (2.1.89)
• Tried both QR code and manual URL entry
• Tried Safari and direct URL paste
• Cleared Safari cookies and re-logged into claude.ai

Verbose Output

Remote Control v2.1.89
Environment ID: env_01DbWoYD4K282bnyRFPTKXen
Connected · Capacity: 0/32
Session started: cse_01Qoamz9L11HyYDgab82teaE

Session registers successfully on the local machine, but the web/mobile side cannot load it. The issue is server-side — the local CLI does everything correctly.

Impact

This is a critical workflow feature. Remote Control is a key reason for the Max subscription — it allows continuing work on local projects (with full filesystem, memory, and tool access) from mobile. Without it, the entire mobile workflow is broken.

Related Issues

• #30473 (Remote not connecting)
• #29855 (/remote-control fails after connecting)
• #28402 (Session not visible in session list)
• #34255 (Connection drops silently)

Please prioritise fixing this. Multiple users appear to be affected.