[BUG] Claude Code on the web stops streaming task progress in desktop WebKit browsers until refresh

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?

Claude Code on the web stops showing live task progress updates in desktop WebKit-based browsers after a task is submitted.

I see the first few lines of task activity / progress feedback, then the page stops updating. The task appears to continue running server-side, because refreshing the page later causes the missing progress/result state to appear.

This reproduces in desktop WebKit-based browsers, including Safari on macOS. I have not tested mobile Safari/iOS. This is not about Claude Code Remote Control.

Chrome and Firefox on the same desktop/network continue showing progress updates correctly.

What Should Happen?

Claude Code on the web should continue streaming live task progress / continuous feedback in desktop WebKit browsers after a task is submitted, without requiring a manual page refresh.

Error Messages/Logs

No visible error message is shown in the Claude Code web UI.

Steps to Reproduce

1. Open Claude Code on the web in desktop Safari on macOS Tahoe 26.5.1.
2. Start a new Claude Code task.
3. Submit a prompt that causes a multi-step task with visible progress output.
4. Observe that Claude initially shows a few progress lines.
5. Leave the page open without refreshing.
6. Observe that progress updates stop appearing in Safari/WebKit.
7. Refresh the page.
8. Observe that additional progress/result content appears after refresh.
9. Repeat the same kind of task in Chrome or Firefox on the same machine/network.
10. Observe that Chrome and Firefox continue showing progress updates correctly.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

N/A - Claude Code on the web / cloud version, not local CLI

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Safari Version 26.5 (latest)