[BUG] Desktop Code tab: Page Up/Page Down stop scrolling only while the composer is focused

What's wrong?

In Claude Desktop, Page Up / Page Down do not scroll the conversation in the Code tab while the message composer/input field has focus.

The important distinction is the focus state:

• Code tab + composer focused: Page Up / Page Down do not scroll the conversation.
• Code tab + composer not focused: Page Up / Page Down scroll normally again.
• Chat + composer focused: Page Up / Page Down work.
• Cowork + composer focused: Page Up / Page Down work.

So this does not appear to be a general Windows keyboard-scrolling problem or a general Claude Desktop problem. It appears specific to how the Code tab handles Page Up / Page Down while its composer has focus.

Steps to reproduce

1. Open Claude Desktop.
2. Switch to the Code tab.
3. Open a conversation long enough to scroll.
4. Click into the message composer so the input field has focus.
5. Press Page Up or Page Down.
6. Observe that the conversation does not scroll.
7. Click outside the composer so the input field no longer has focus.
8. Press Page Up or Page Down again.
9. Observe that scrolling now works.

Control test:

1. Switch to Chat or Cowork.
2. Keep the composer focused.
3. Press Page Up / Page Down.
4. The conversation scrolls normally.

Expected behavior

Page Up / Page Down should scroll the conversation in the Code tab even while the composer is focused, matching Chat and Cowork.

Why this looks surface-specific

This is effectively the reverse of #65688, which reported that Page Up / Page Down worked in Code but not in Cowork.

#65688 was later closed as a duplicate of #62880. The current behavior is different: Cowork now works, while Code fails only when the composer has focus.

Related keyboard/focus tracking issue: #90761.

Impact

This is particularly disruptive for keyboard-only navigation and assistive input workflows because reading back through a long conversation requires leaving the composer before Page Up / Page Down can be used.

Workaround: Press Tab to move focus out of the composer. Page Up / Page Down then work immediately.

Environment

• Claude Desktop
• Windows