MOBI table of contents broken in Buckram updated themes

[mcgratay]

Prerequisites

• Can you reproduce the behavior you wish to address with all plugins except Pressbooks deactivated?
• Are you running the latest version of Pressbooks, the latest version of McLuhan, and the latest version of WordPress?
• Are you experiencing the issue while using this book theme?
• Did you perform a cursory search to see if your bug or enhancement is already listed?

Description

Chapters and other links on the MOBI table of contents cannot be clicked on books that have a Buckram theme applied. These files get rejected from KDP.

Example: https://carmenmobitoc.textopress.com/

Steps to Reproduce

1. Create a new book or access an existing test book
2. Go to Appearance > Themes and apply an updated Buckram theme (ex: Austen)
3. Go to Exports and export a MOBI file
4. Download the MOBI file and view Kindle Previewer
5. Check table of contents

Expected behavior: Chapters in the table of contents can be clicked to navigate the MOBI ebook.

Actual behavior: Links in the table of contents do not function when certain book themes are activated.

[mcgratay]

Resolved.