[BUG] Cowork microphone input cuts off after ~2 seconds on x64 — works fine on ARM64

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?

Title:

[BUG] Cowork microphone input cuts off after ~2 seconds on x64 — works fine on ARM64
Body:
Environment A (broken):

Windows 11, x64 desktop, Realtek + Puck UM02 USB microphone (tested both)
Environment B (working):

Windows 11 Home, ARM64 (Surface Pro, Snapdragon X), Qualcomm Aqstic audio
What's wrong:

Microphone input in Cowork cuts off after approximately 2 seconds, capturing only a few syllables — regardless of whether I speak continuously or pause. Same Claude account and Cowork setup works correctly on the ARM64 machine.
Steps to reproduce:

Open a Cowork tab in Claude Desktop on an x64 Windows machine
Click the microphone button and speak continuously for more than 2-3 seconds
Observe that input capture stops after ~2 seconds regardless of pausing

Already ruled out:

Microphone hardware/drivers — tested 3 different physical microphones, same result
USB power management, exclusive mode, audio enhancements
Windows Voice Access and Dragon NaturallySpeaking — both work fine outside Cowork on the same machine
Cowork VM startup health — resolved an unrelated VHDX compression/sparse-attribute error (HRESULT 0xC03A001A), confirmed VM now starts cleanly; mic cutoff identical before and after
A custom scheduled task forcing Claude.exe to High CPU priority — confirmed present and running identically on both the x64 and ARM64 machines, so not the differentiator
Hyper-V compute service (vmcompute) availability — confirmed Running on both machines

Likely area:

Audio capture/transcription pipeline within Cowork. Given it reproduces consistently on x64 and not on ARM64 with otherwise equivalent setups, this may be an architecture-specific issue (e.g., a timeout or buffer constant tuned for one platform).
Impact:

Blocking — voice dictation is the primary input method for my Cowork workflow.

What Should Happen?

I have extensively troublshot and cleaned out registry etc. need help!

Error Messages/Logs

Steps to Reproduce

Steps to reproduce:

Open Claude Desktop on a Windows 11 x64 machine
Open or start a Cowork task
Click the microphone/voice input button in the Cowork chat input
Speak continuously for at least 5 seconds without pausing
Observe that audio capture stops being recognized after approximately 2 seconds — only the first few syllables are picked up, even though you're still speaking

Expected: Microphone should continue capturing audio for as long as the mic button is active / as long as you're speaking.
Actual: Capture cuts off after ~2 seconds regardless of continuous speech.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.15962.1.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

N/A (Cowork GUI, not terminal-base