Bug: Backspace stops working after concurrent subprocesses on Windows

What version of Codex CLI is running?

0.134.0

What subscription do you have?

Plus

Which model were you using?

gpt-5.5 default

What platform is your computer?

Windows 10

What terminal emulator and version are you using (if applicable)?

Windows command

Codex doctor report

codex doctor --json completed successfully.

  Overall status: ok
  Codex version: 0.134.0
  Notable details:

  - Auth configured with ChatGPT tokens and OPENAI_API_KEY present
  - Network and WebSocket reachability both ok
  - Installation is npm-managed on Windows x86_64
  - No MCP servers configured
  - Current version matches latest cached version: 0.134.0

What issue are you seeing?

In codex installed on windows, certain commands corrupts the prompt. Backspace adds characters in stead of deleting them.

What steps can reproduce the bug?

Grant full permissions, and provide this exact prompt (this reproduces it almost always):

Run this command:
powershell powershell -NoProfile -Command "$p1 = Start-Process wsl -ArgumentList '-- echo ONE' -PassThru -NoNewWindow; $p2 = Start-Process wsl -ArgumentList '-- echo TWO' -PassThru -NoNewWindow; Wait-Process -Id $p1.Id,$p2.Id

What is the expected behavior?

Backspace should work properly after codex completes a prompt.

Additional information

_No response_