Scroll position jumps to top during streaming output on Windows Terminal

[NKM4]

Description

While Claude Code is streaming a response, if you scroll up using the mouse wheel, the scroll position frequently jumps back to the very top of the terminal. This makes it impossible to review earlier parts of the conversation during generation.

Reproduction steps

1. Use Claude Code in Windows Terminal until the conversation is long enough to scroll
2. Ask a question that produces a long streaming response
3. While the response is being generated, scroll up with the mouse wheel
4. The viewport jumps to the very top of the terminal buffer

Key observations

• Only happens during streaming — once generation completes and the input prompt appears, scrolling works normally
• Likely related to cursor repositioning / ANSI escape sequences used for spinner or status line updates during streaming, which interfere with Windows Terminal's scroll position

Environment

• Claude Code: 2.1.80
• OS: Windows 11 Pro (10.0.26200)
• Terminal: Windows Terminal
• Shell: bash (Git Bash)

🤖 Generated with Claude Code

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] Terminal scrolls to top during agent execution (Windows Terminal + PowerShell) #34794
2. Root cause + fix for scroll jumping on long responses (CSI 2J inside DEC 2026 sync blocks) #35580
3. Terminal scrolls to top on every new output in certain sessions #34503

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🤖 Generated with Claude Code

[nullbio]

Still broken as of v2.1.81:

#36582
#35403
#36816
#35683
#33814
#34845
#33367
#34400
#826
#36621
#36128
#35766
#34242
#18299