Emoji shortcodes not rendered as emojis in in-page TOC

[hkosova]

CLI Version (from fern.config.json)

0.46.22

Minimal API Specification

n/a

Actual UI Behavior

If header text includes an emoji shortcode such as :eu:, the header itself renders that emoji but the in-page table of contents displays the shortcode as is.

Expected UI Behavior

Emojis are rendered in the in-page TOC.

Steps to Reproduce

Sample .mdx page to reproduce the issue:

---
title: Test
---

## :eu: EU

## :uk: UK

## :us: US

{/* But the following headers are displayed correctly in in-page TOC */}

## 🇪🇺 EU

## 🇪🇺 EU

Workaround

Either insert the emoji character as-is into Markdown, or use HTML character codes &#....

Environment Details

Chrome, Safari on macOS 15