[BUG] **VSCode-Ext-Streaming not working - text appears all at once after ~20 seconds-**

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?

PS : link to VSCode Extension. Last working 2.1.37 (CC 2.1.49)

• Claude Code versions tested: 2.1.49, 2.1.39, 2.1.37
• Platforms tested: Windows PowerShell (native), Linux Debian LXC (SSH)
• Tabby / VSExtension + terminal / Proxmox Console. Powershell windows (Debain Linux 13 on 2 separate install, one fresh)
• All models affected: Opus, Sonnet, Haiku
• claude.ai web streaming works fine
• Was working ~4 days ago (Feb 16)

What Should Happen?

CLaude answer should be stream word by word, not the full message. Samebehavior with the thinking, all the message come ine 1 block.

Error Messages/Logs

Debug log shows:
  - blit=0, 100% writes on every frame
  - useDeferredValue defers all intermediate renders
  - 20-second gap between first chunk and final render
  - Token counter updates in real-time, only text rendering is blocked

Steps to Reproduce

Ask to claude to write 500 words on any subject

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version VSCode

2.1.37

Claude Code Version

2.1.49

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Tabby / VSExtension + terminal / Proxmox Console. Powershell windows (Debain Linux 13 on 2 separate install, one fresh)
PowerShell native

Additional Information

_No response_