[BUG] Missing top lines of output

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?

Hello, I've seen this several times over the last few weeks, where the top few lines of Claude's output is missing. When working on Python code, it's usually a few lines of import statements that are missing, and asking for the first few lines again usually seems to work.

I just now saw this happen with "plan" output rather than code written to the terminal:

● Good, we don't track generations yet. Now let me update the design with refined message formats:

●















      /// Number of unique file contents (after deduplication)
      pub unique_content_entries: u64,

      /// Index settings applied during indexing
      pub index_settings: IndexSettings,

      /// Tags for grouping/filtering (e.g., ["prod", "us-west", "rust-repos"])
      pub tags: Vec<String>,

      /// When the index was last updated
      pub last_updated: i64,  // Unix timestamp
  }
  [... from here it's all fine ...]

Thanks

What Should Happen?

Ideally, the entire "intended output" would be visible on my terminal.

Error Messages/Logs

Steps to Reproduce

I'm using Ubuntu 24.04 LTS and tmux via ssh in urxvt.

Have a few small pieces of conversation back and forth and then ask Claude to design something that ought to take more than a single terminal to show it all. (I think I've only seen this when the output doesn't fit in a single terminal.)

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.8 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

_No response_