[BUG] Forked conversations sometimes disappear when resuming

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Description

Forked conversations intermittently disappear when attempting to resume them using claude --resume or claude --continue. This appears to happen randomly and without any clear error message or warning.

A previously visible forked thread will sometimes no longer appear in the conversation list or cannot be resumed after navigating away, refreshing, or restarting the session.

This disrupts workflow, especially when using forks to explore alternative implementations.

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Steps to Reproduce

1. Start a conversation through normal claude code in the CLI.
2. Go to another terminal and do claude --continue --fork-session
3. Continue interacting within the fork.
4. Navigate away (reload page / switch session / close & reopen).
5. Attempt to resume the forked conversation using claude --resume or claude --continue

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Actual Behavior

The forked conversation sometimes disappears entirely from the conversation list or becomes inaccessible when attempting to resume it.

No visible error is shown in the UI.

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Frequency

Intermittent - not consistently reproducible, but happens often enough to impact development flow.

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Things Tried

• Restarted Claude Code.
• Refreshed the session.
• Checked the local .claude directory to see if the conversation files still existed.
• Looked for forked conversation IDs manually in .claude to attempt recovery.
• Confirmed this was not just a UI filtering issue.
• Verified no manual deletion was performed.

In some cases, the forked conversation does not appear to be present in .claude, suggesting it may not have been persisted correctly.

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Environment

• macOS: macOS Tahoe 26.3
• Claude Code: Latest published version v2.1.39

What Should Happen?

The forked conversation should persist and remain accessible in the conversation history through resume flag or continued through continue flag, allowing it to be resumed normally.

Error Messages/Logs

Steps to Reproduce

1. Start a conversation through normal claude code in the CLI.
2. Go to another terminal and do claude --continue --fork-session
3. Continue interacting within the fork.
4. Navigate away (reload page / switch session / close & reopen).
5. Attempt to resume the forked conversation using claude --resume or claude --continue

Claude Model

Opus4.6

Claude Code Version

v2.1.39

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_