Review panel stays on "Loading diff" and never renders file diffs for unstaged changes

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

Codex 26.409.61251

What subscription do you have?

pro

What platform is your computer?

Microsoft Windows NT 10.0.19045.0 x64

What issue are you seeing?

<img width="569" height="260" alt="Image" src="https://github.com/user-attachments/assets/d8c82d96-33fd-46fd-9bc6-a7ce805e62d9" />

When opening the Review tab in Codex, file entries never render their diffs and stay stuck on Loading diff.

What I tested:

Unstaged tracked file change: README.md
Unstaged untracked file: TEMP_REVIEW_TEST.md
Previously also tested normal text files like scripts/version.py and tests/test_version.py
Observed behavior:

The Review tab lists the files correctly
Each file shows Loading diff
The diff content never appears
Examples from the UI:

README.md -> Loading diff
TEMP_REVIEW_TEST.md -> Loading diff

What steps can reproduce the bug?

Open a local Git repository in Codex on Windows.
Make an unstaged change to a tracked text file, for example edit README.md.
Optionally create an untracked text file, for example TEMP_REVIEW_TEST.md.
Open the Review tab in Codex.
Look at the file entries under unstaged changes.
Expected:

Codex renders the diff for each changed file.
Actual:

The files appear in the list, but each one stays on Loading diff indefinitely.
No diff content is shown.
Minimal reproduction example:

In a Git repo, modify a tracked file:
README.md

• <!-- TEMP_REVIEW_TEST: unstaged tracked-file change -->

Leave it unstaged.
Open Codex Review.
The file is listed, but the panel never shows the diff.
Notes:

git diff in the terminal works normally for the same files.
This also reproduces for an untracked text file, not just tracked files.
I do not have the Codex session id, token usage, or context window usage from the UI to provide.

What is the expected behavior?

In the Review tab, Codex should render the actual Git diff for changed files instead of staying on Loading diff.

For example:

For an unstaged tracked file like README.md, it should show the added/removed lines.
For an unstaged untracked text file like TEMP_REVIEW_TEST.md, it should show the file contents as a new-file diff.
The diff should appear within a few seconds and remain viewable without needing to restart Codex.

Additional information

_No response_