Codex Desktop macOS: block Copy button clicks but leaves clipboard unchanged

What version of the Codex App are you using (From “About Codex” dialog)?

26.611.62324

What subscription do you have?

Pro

What platform is your computer?

macOS 15.7.7 (24G720), arm64, MacBookPro18,3

What issue are you seeing?

In Codex Desktop conversation blocks, the visible block-level Copy button/icon can be clicked, but it does not write anything to the macOS clipboard. The clipboard contents remain exactly what they were before the click.

This is different from #20748. In this case the button is visible and receives the click; the problem is that the copy action appears to be a no-op.

I verified this with a sentinel clipboard test:

1. Set the macOS clipboard to CODEX_COPY_SENTINEL_BEFORE_CLICK_0200.
2. Activated the Codex app.
3. Clicked a visible block-level copy control in the transcript using a real mouse event (CGEvent mouse down/up at the visible button coordinate).
4. Read the macOS clipboard again.

Actual readback was still:

CODEX_COPY_SENTINEL_BEFORE_CLICK_0200

So the UI click did not update the pasteboard.

What steps can reproduce the bug?

1. Open Codex Desktop on macOS.
2. Open a thread with conversation blocks.
3. Put known text on the clipboard in another app or via pbcopy/AppleScript.
4. Hover a conversation block until its Copy button/icon is visible.
5. Click the visible Copy button/icon.
6. Paste into another app or inspect the clipboard.

What is the expected behavior?

Clicking the visible block-level Copy button should replace the clipboard with the corresponding block/message text.

What is the actual behavior?

The clipboard is unchanged. There is no visible error or failure indication.

Additional information

This was observed on user/conversation blocks in Codex Desktop. It appears to be a clipboard-write failure or handler no-op, not a hit-target issue where a side panel intercepts the click.