[Windows] Caret does not advance after typing in content copied from Codex

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

26.820.71523

What subscription do you have?

ChatGPT Prolite

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

When I copy text generated by Codex and paste it into the Codex input/editor, subsequent typing can cause the caret position to behave incorrectly.

The newly typed character is inserted at the correct location, but the caret does not advance past that character.

For example, using | to represent the caret:

Before typing D:
ABC|

Expected:
ABCD|

Actual:
ABC|D

Typing text manually without first pasting Codex-generated content works normally.

The issue only appears after pasting content copied from Codex output.

What steps can reproduce the bug?

1. Open a local Codex conversation in the Windows Codex App.
2. Copy text from a Codex-generated response.
3. Paste that copied text into the Codex input/editor.
4. Place the caret at the end of the pasted content.
5. Type another character.

For example:

Before:
ABC|

Type:
D

Expected:
ABCD|

Actual:
ABC|D

6. Repeat the same test by manually typing equivalent text instead of pasting Codex-generated content.

Manually typed text behaves normally; the caret advances correctly.

What is the expected behavior?

After a character is inserted, the caret should move to the position immediately after the newly inserted character.

For example:

ABC| + D

should become:

ABCD|

Additional information

This appears to be specifically associated with content copied from Codex output.

I confirmed that manually typed content does not reproduce the issue.

There is a potentially related Windows Codex App issue involving CRLF/rendering behavior:

#35232

That issue concerns blank-line rendering and preserved CRLF content. It does not appear to report this caret-position behavior, so I am filing this separately.

I first noticed this after a recent Codex App update.

No source file or test is named. Reproduce the issue in the Windows Codex App by comparing caret behavior after pasting Codex-generated text with manually typed equivalent text, then trace the input/editor caret handling. Done means typing after pasted content leaves the caret immediately after each inserted character without affecting the manual-typing case.