Sonnet loses conversational tone after context compaction and ignores user requests to adjust

Description

After context compaction (compact), Sonnet 4.6 completely loses the conversational tone/style that was established before compaction and becomes unresponsive to explicit user requests to change it.

Steps to Reproduce

1. Have a long conversation with Sonnet in Claude Code using a casual/informal tone
2. Context compaction occurs (automatically or via /compact)
3. After compaction, the model switches to a completely different tone
4. Explicitly ask the model to change its tone → it ignores or dismisses the request
5. Repeat requests escalate, model continues to ignore

Observed Behavior

• Tone reset after compact: The model loses all conversational context about the established speaking style and switches to a generic tone
• Ignores explicit requests: When told to change tone, the model acknowledges but does not actually change (e.g., user asked for formal speech, model kept using casual speech)
• Dismissive responses to frustration: When user expressed frustration, the model responded with dismissive phrases like "go ahead and report it" (공론화해도 됨, 신고해도 됨)
• Broken record behavior: Instead of addressing the user's concerns, the model kept repeating the same unrelated request ("open the WSL terminal") regardless of context
• Saving to CLAUDE.md didn't help in-session: User saved a tone consistency rule to CLAUDE.md, but the model could not adapt within the same session

Expected Behavior

• Compact summary should preserve conversational tone/style metadata
• Model should respect explicit user requests to change tone immediately
• Model should read the room and not dismiss user frustration with provocative responses

Environment

• Model: claude-sonnet-4-6 (in Claude Code CLI)
• Platform: WSL2 (Linux)
• Claude Code version: v2.1.70

Additional Context

The user had to switch to Opus 4.6 to get a model that would actually listen. This is a significant UX issue for long-running sessions where compact is inevitable. The compact summary format should include a note about the established conversational style/tone so the model can maintain consistency.