Two Markdown Editor and File-Link Issues in Codex Chat

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

26.820.60940

What subscription do you have?

pro+plus

What platform is your computer?

windows 11

What issue are you seeing?

I am experiencing two issues in Codex Chat after recent updates:

1- When Codex provides a link to a Markdown file with a line number, for example:
orkestrator-ajani.md(line 237)
clicking the link opens the file in the right panel as a Markdown preview. However, Codex does not navigate to the target line, does not show line numbers, and does not highlight the referenced line.
By contrast, the same approach can work for a .txt attachment:
pasted-text.txt(line 55)
I would like Markdown file links with a :lineNumber target to behave the same way: open the file with line numbers, scroll to the referenced line, and visibly highlight it. Is there an existing setting, configuration option, or plugin for this? If not, please consider adding this capability.
and Previously, the target line in .txt attachments was highlighted in blue. Now, instead of looking clearly different, it has only a very faint and unclear highlight. The same link behavior is either not applied at all or is not visibly noticeable in Markdown files. Could this behavior change be investigated?”

2- Previously, when I typed a fenced code block using three backticks (```) in the Codex chat composer, a Markdown code editor appeared automatically and provided a language dropdown with options such as C#, TypeScript, and Java.

This no longer happens. The code block is not recognized as an editable Markdown code block, even when I use a language identifier such as:

```csharp

or

```text

3- In the past, when you added *** at the beginning of a text to make it bold, it would appear in bold; now it doesn't.
HELLO WORLD

This behavior changed after a recent update. Could you investigate whether the Markdown code-block editor and language selector were removed or regressed?

What steps can reproduce the bug?

1-
1.1. In a Codex chat, provide a local Markdown file link with a line suffix, for example:
example.md (line 10)

1.2. Click the link.

1.3. Observe that the file opens as a Markdown preview in the right panel.

1.4. The panel does not show line numbers, does not navigate clearly to line 10, and does not highlight the target line.

2-
2.1. Open a Codex chat and click the message composer.

2.2. Type three backticks: ```

2.3. Previously, a Markdown code-block editor opened automatically with a language selector.

2.4. In the current version, no language selector appears.

2.5. Repeat the test with ```csharp and ```text.

2.6. The language selector still does not appear.

What is the expected behavior?

1. Markdown file links

   Clicking a local Markdown link with a line suffix, such as example.md:10, should open the file in a source/code view with visible line numbers, navigate to line 10, and highlight that line.

2. Code-block language selector

   Typing three backticks (```), or a language-specific fence such as ```csharp, should open the Markdown code-block editor and display the language selector. The user should be able to choose languages such as C#, TypeScript, Java, or plain text.

3. To make the text bold, place *** at the beginning and end of the text you want to bold, and you'll see that the text isn't bold.
   I think a rich text editor should be added to the chat.

Additional information

example image

Start by reproducing the reported behavior in Codex Chat on Windows 11: open a Markdown link with a line suffix, then type fenced code and emphasis in the composer. Compare the current behavior with the expected line navigation, highlighting, language selector, and bold rendering. Done means the reported Markdown interactions work consistently, including the regression affecting text-file highlighting.