[BUG] Saved language/tone preferences in memory are not applied consistently across sessions

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?

A preference saved in memory (to use neutral Spanish without the "voseo" form) is not retained across sessions; it is treated as background context with recall based on relevance, so it is not applied during long sessions or sessions on other topics.

What Should Happen?

A preference stored in user memory (e.g. language or tone) should be applied consistently across all sessions and projects — not only when the system deems it "relevant." If I explicitly saved "always use neutral Spanish, no voseo," that should be honored from the start of every session with the weight of an instruction, not treated as optional background context that can be ignored. At minimum, persistent behavioral preferences (language, tone, formatting) should be loaded reliably every session rather than depending on relevance-based recall.

Error Messages/Logs

Steps to Reproduce

1. In a session, save a persistent behavioral preference to user memory — e.g. "always use neutral Spanish, no voseo / no regional slang, both in chat and in generated UI text."
2. Confirm the memory file is written and indexed in MEMORY.md.
3. Start a new, unrelated session (different topic or project) days later.
4. Interact in Spanish over a long conversation.

Result: Claude reverts to voseo / regional forms, ignoring the saved preference. The full memory content is only pulled into context when deemed "relevant," and even then it's treated as background context rather than a binding instruction — so the preference is applied inconsistently across sessions.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.116 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_